Publications by authors named "Mats Lekander"

137 Publications

Regulation of emotions during experimental endotoxemia: A pilot study.

Brain Behav Immun 2021 Jan 22. Epub 2021 Jan 22.

Stress Research Institute, Department of Psychology, Stockholm University, 10691 Stockholm, Sweden; Department of Clinical Neuroscience, Division of Psychology, Karolinska Institutet, Nobels väg 9, 17177 Stockholm, Sweden; Department of Clinical Neuroscience, Osher Center for Integrative Medicine, Karolinska Institutet, Nobels väg 9, 17177 Stockholm, Sweden. Electronic address:

Even though dysfunctional emotion regulation is prominent in depression and a link between depression and inflammation is well established, there is little knowledge about how inflammation affects the regulation of emotions. The aim of this pilot study was to explore the effect of experimentally induced inflammation on the cognitive reappraisal of emotions, and to assess domain specificity by comparing success in regulation of emotions towards two unpleasant stimuli classes (general negative stimuli and disgust stimuli). In a between-subject design, ten healthy participants were injected with an intravenous injection of lipopolysaccharide (2 ng/kg body weight) and eleven were injected with saline. Participants performed a cognitive reappraisal task, in which they had to down-regulate or up-regulate their emotions towards general negative stimuli and disgust stimuli, 5-6 h post-injection. Contrary to our hypotheses, participants injected with lipopolysaccharide reported greater success in down-regulating emotional responses towards unpleasant stimuli as compared to the saline group. In addition, both groups were poorer at down-regulating emotions towards disgust stimuli as compared to general negative stimuli. The current pilot study indicates that cognitive reappraisal of emotions is affected during experimental endotoxemia, and suggests that disgust stimuli might be difficult to reappraise.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bbi.2021.01.013DOI Listing
January 2021

Internet-delivered acceptance and commitment therapy as microlearning for chronic pain: A randomized controlled trial with 1-year follow-up.

Eur J Pain 2021 Jan 18. Epub 2021 Jan 18.

Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.

Background: Studies of Internet-delivered acceptance and commitment therapy (ACT) for chronic pain have shown small to moderate positive effects for pain interference and pain acceptance. Effects on pain intensity, depression, anxiety and quality of life (QoL) have been less favourable, and improvements for values and sleep are lacking. In this randomized controlled trial iACT - a novel format of Internet-ACT using daily microlearning exercises - was examined for efficacy compared to a waitlist condition.

Methods: Adult participants (mean age 49.5 years, pain duration 18.1 years) with diverse chronic pain conditions were recruited via self-referral, and randomized to iACT (n = 57) or waitlist (n = 56). The primary outcome was pain interference. The secondary outcomes were QoL, depression, anxiety, insomnia and pain intensity. The process variables included psychological inflexibility and values. Post-assessments were completed by 88% (n = 100) of participants. Twelve-month follow-up assessments were completed by 65% (iACT only, n = 37). Treatment efficacy was analysed using linear mixed models and an intention-to-treat-approach.

Results: Significant improvements in favour of iACT were seen for pain interference, depression, anxiety, pain intensity and insomnia, as well as process variables psychological inflexibility and values. Between-group effect sizes were large for pain interference (d = 0.99) and pain intensity (d = 1.2), moderate for anxiety and depressive symptoms and small for QoL and insomnia. For the process variables, the between-group effect size was large for psychological inflexibility (d = 1.0) and moderate for values. All improvements were maintained at 1-year follow-up.

Conclusions: Internet-ACT as microlearning may improve a broad range of outcomes in chronic pain.

Significance: The study evaluates a novel behavioral treatment with positive results on pain interference, mood as well as pain intensity for longtime chronic pain sufferers. The innovative format of a digital ACT intervention delivered in short and experiential daily learnings may be a promising way forward.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/ejp.1723DOI Listing
January 2021

Vulnerability in Executive Functions to Sleep Deprivation Is Predicted by Subclinical Attention-Deficit/Hyperactivity Disorder Symptoms.

Biol Psychiatry Cogn Neurosci Neuroimaging 2020 Oct 29. Epub 2020 Oct 29.

Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden. Electronic address:

Background: Sleep loss results in state instability of cognitive functioning. It is not known whether this effect is more expressed when there is an increased cognitive demand. Moreover, while vulnerability to sleep loss varies substantially among individuals, it is not known why some people are more affected than others. We hypothesized that top-down regulation was specifically affected by sleep loss and that subclinical inattention and emotional instability traits, related to attention-deficit/hyperactivity disorder symptoms, predict this vulnerability in executive function and emotion regulation, respectively.

Methods: Healthy subjects (ages 17-45 years) rated trait inattention and emotional instability before being randomized to either a night of normal sleep (n = 86) or total sleep deprivation (n = 87). Thereafter, they performed a neutral and emotional computerized Stroop task, involving words and faces. Performance was characterized primarily by cognitive conflict reaction time and reaction time variability (RTV), mirroring conflict cost in top-down regulation.

Results: Sleep loss led to increased cognitive conflict RTV. Moreover, a higher level of inattention predicted increased cognitive conflict RTV in the neutral Stroop task after sleep deprivation (r = .30, p = .0055) but not after normal sleep (r = .055, p = .65; interaction effect β = 6.19, p = .065). This association remained after controlling for cognitive conflict reaction time and emotional instability, suggesting domain specificity. Correspondingly, emotional instability predicted cognitive conflict RTV for the emotional Stroop task only after sleep deprivation, although this effect was nonsignificant after correcting for multiple comparisons.

Conclusions: Our findings suggest that sleep deprivation affects cognitive conflict variability and that less stable performance in executive functioning may surface after sleep loss in vulnerable individuals characterized by subclinical symptoms of inattention.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bpsc.2020.09.019DOI Listing
October 2020

Internet-delivered cognitive behaviour therapy for adolescents with insomnia comorbid to psychiatric conditions: A non-randomised trial.

Clin Child Psychol Psychiatry 2020 Dec 18:1359104520978464. Epub 2020 Dec 18.

Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.

Insomnia is highly prevalent among adolescents with psychiatric conditions and is known to aggravate psychiatric symptoms. Research on cognitive behaviour therapy for adolescents with comorbid insomnia (CBT-I) is still limited. The aim of this study was to investigate feasibility and preliminary effects of internet-delivered CBT for adolescents with insomnia comorbid to a psychiatric condition. Twenty-one patients (13-17 years) with comorbid insomnia were recruited from Child and Adolescent Psychiatry. All patients received 7 weeks of internet-delivered CBT-I with therapist support. Outcomes were assessed at baseline, post-treatment, and at a 4-month follow-up. The proportion of completed assessments was overall acceptable. Participants on average completed 4.48 ( = 1.97) of the seven treatment modules and therapists on average spent 12.80 minutes ( = 6.23) per patient and week. Results showed large statistically significant improvements on insomnia severity, sleep efficiency, sleep onset latency and sleep quality. Medium to large improvements were also seen on the psychiatric symptoms of depression, obsessive-compulsive symptoms, interpersonal sensitivity, paranoid ideation and psychoticism. These findings indicate that internet-delivered CBT is feasible and potentially promising for improving sleep and reducing psychiatric symptoms in adolescent psychiatric patients with insomnia and co-morbid psychiatric disorders. A larger randomised trial is warranted to verify these preliminary results.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/1359104520978464DOI Listing
December 2020

The mediating role of insomnia severity in internet-based cognitive behavioral therapy for chronic stress: Secondary analysis of a randomized controlled trial.

Behav Res Ther 2021 Jan 27;136:103782. Epub 2020 Nov 27.

Department of Clinical Neuroscience, Division of Psychology, Karolinska Institutet, Stockholm, Sweden; Osher Center for Integrative Medicine, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.

The aim of this study was to investigate insomnia symptom severity as a putative mediator of treatment response in therapist-guided internet-based cognitive behavioral therapy (ICBT) for chronic stress, using data from a randomized controlled trial. Participants (N = 100) were randomized to 12 weeks of ICBT or to a waitlist control condition (WLC). Insomnia severity was assessed weekly with the Insomnia Severity Index (ISI), as were the stress-related outcomes the Perceived Stress Scale (PSS) and the Shirom-Melamed Burnout Questionnaire (SMBQ). Latent growth models indicated that ICBT (vs. WLC) predicted a decrease in insomnia severity (α-path), and that growth in insomnia severity was predictive of growth in perceived stress and exhaustion (β-paths). Most importantly, there were also significant indirect effects (αβ products) such that the beneficial effects of ICBT on perceived stress and exhaustion were mediated by a reduction in insomnia symptom severity (PSS: αβ = -0.44, 95% CI [-0.92, -0.14]; SMBQ: αβ = -0.08, 95% CI [-0.15, -0.04]). Explorative analysis of moderated mediation showed that more severe insomnia symptoms at baseline were associated with larger mediated effects. We conclude that reducing insomnia severity could be of importance for achieving successful treatment outcomes in ICBT for chronic stress.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.brat.2020.103782DOI Listing
January 2021

A combined fMRI and EMG study of emotional contagion following partial sleep deprivation in young and older humans.

Sci Rep 2020 10 21;10(1):17944. Epub 2020 Oct 21.

Stress Research Institute, Department of Psychology, Stockholm University, Stockholm, Sweden.

Sleep deprivation is proposed to inhibit top-down-control in emotion processing, but it is unclear whether sleep deprivation affects emotional mimicry and contagion. Here, we aimed to investigate effects of partial sleep deprivation on emotional contagion and mimicry in young and older humans. Participants underwent partial sleep deprivation (3 h sleep opportunity at the end of night), crossed-over with a full sleep condition in a balanced order, followed by a functional magnetic resonance imaging and electromyography (EMG) experiment with viewing of emotional and neutral faces and ratings of emotional responses. The final sample for main analyses was n = 69 (n = 36 aged 20-30 years, n = 33 aged 65-75 years). Partial sleep deprivation caused decreased activation in fusiform gyri for angry faces and decreased ratings of happiness for all stimuli, but no significant effect on the amygdala. Older participants reported more anger compared to younger participants, but no age differences were seen in brain responses to emotional faces or sensitivity to partial sleep deprivation. No effect of the sleep manipulation was seen on EMG. In conclusion, emotional contagion, but not mimicry, was affected by sleep deprivation. Our results are consistent with the previously reported increased negativity bias after insufficient sleep.The Stockholm sleepy brain study: effects of sleep deprivation on cognitive and emotional processing in young and old. https://clinicaltrials.gov/ct2/show/NCT02000076 .
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-020-74489-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7578048PMC
October 2020

Cortical thickness and resting-state cardiac function across the lifespan: A cross-sectional pooled mega-analysis.

Psychophysiology 2020 Oct 10. Epub 2020 Oct 10.

Norwegian Centre for Mental Disorders Research (NORMENT), Institute of Clinical Medicine, University of Oslo, Oslo, Norway.

Understanding the association between autonomic nervous system [ANS] function and brain morphology across the lifespan provides important insights into neurovisceral mechanisms underlying health and disease. Resting-state ANS activity, indexed by measures of heart rate [HR] and its variability [HRV] has been associated with brain morphology, particularly cortical thickness [CT]. While findings have been mixed regarding the anatomical distribution and direction of the associations, these inconsistencies may be due to sex and age differences in HR/HRV and CT. Previous studies have been limited by small sample sizes, which impede the assessment of sex differences and aging effects on the association between ANS function and CT. To overcome these limitations, 20 groups worldwide contributed data collected under similar protocols of CT assessment and HR/HRV recording to be pooled in a mega-analysis (N = 1,218 (50.5% female), mean age 36.7 years (range: 12-87)). Findings suggest a decline in HRV as well as CT with increasing age. CT, particularly in the orbitofrontal cortex, explained additional variance in HRV, beyond the effects of aging. This pattern of results may suggest that the decline in HRV with increasing age is related to a decline in orbitofrontal CT. These effects were independent of sex and specific to HRV; with no significant association between CT and HR. Greater CT across the adult lifespan may be vital for the maintenance of healthy cardiac regulation via the ANS-or greater cardiac vagal activity as indirectly reflected in HRV may slow brain atrophy. Findings reveal an important association between CT and cardiac parasympathetic activity with implications for healthy aging and longevity that should be studied further in longitudinal research.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/psyp.13688DOI Listing
October 2020

Cognitive-behavioral therapy for insomnia in adolescents with comorbid psychiatric disorders: A clinical pilot study.

Clin Child Psychol Psychiatry 2020 Oct 17;25(4):958-971. Epub 2020 Jun 17.

Department of Clinical Neuroscience, Karolinska Institutet, Sweden.

Background: Insomnia is common in adolescents and often comorbid with psychiatric disorders. This study evaluated changes in insomnia, sleep, and comorbid symptoms following cognitive-behavioral therapy for insomnia (CBT-I) in adolescents with comorbid psychiatric disorders and chronic pain.

Methods: In this non-controlled clinical pilot study, participants ( = 23, 78% female) were recruited from adolescent psychiatry and pediatric pain clinics. Assessments of self-reported insomnia, sleep onset latency, wake after sleep onset, total sleep time, sleep efficiency and depression, anxiety, functional disability, and pain intensity were completed at pre- and post-intervention and 3 months follow-up.

Results: From pre- to post-intervention, statistically significant improvements were found for insomnia symptoms ( < .001;  = 1.63), sleep onset latency ( < .001;  = 1.04), wake after sleep onset ( < .001;  = 0.38), total sleep time ( = .015;  = 0.22), sleep efficiency ( < .001;  = 1.00), depression ( < .001;  = 0.87), and anxiety ( = .001;  = 0.31). Only eight participants reported data at follow-up with maintained improvements for all measures.

Conclusion: This study provides support that insomnia symptoms and sleep can improve following CBT-I delivered in a clinical setting and that co-occurring psychiatric symptoms can be reduced. The results should be interpreted with caution due to the uncontrolled conditions and limited sample size. Well-powered clinical trials are needed to validate the suggested effects.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/1359104520929376DOI Listing
October 2020

Sick for science: experimental endotoxemia as a translational tool to develop and test new therapies for inflammation-associated depression.

Mol Psychiatry 2020 Sep 1. Epub 2020 Sep 1.

Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, University of Duisburg-Essen, Hufelandstrasse 55, 45122, Essen, Germany.

Depression is one of the global leading causes of disability, but treatments remain limited and classical antidepressants were found to be ineffective in a substantial proportion of patients. Thus, novel effective therapies for the treatment of depression are urgently needed. Given the emerging role of inflammation in the etiology and pathophysiology of affective disorders, we herein illustrate how experimental endotoxemia, a translational model of systemic inflammation, could be used as a tool to develop and test new therapeutic options against depression. Our concept is based on the striking overlap of inflammatory, neural, and affective characteristics in patients with inflammation-associated depression and in endotoxin-challenged healthy subjects. Experimental administration of endotoxin in healthy volunteers is safe, well-tolerated, and without known long-term health risks. It offers a highly standardized translational approach to characterize potential targets of therapies against inflammation-associated depression, as well as to identify characteristics of patients that would benefit from these interventions, and, therefore, could contribute to improve personalization of treatment and to increase the overall rate of responders.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41380-020-00869-2DOI Listing
September 2020

Internet-delivered acceptance and commitment therapy (iACT) for chronic pain-feasibility and preliminary effects in clinical and self-referred patients.

Mhealth 2020 5;6:27. Epub 2020 Jul 5.

Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.

Background: Acceptance and commitment therapy (ACT) is an evidence-based treatment to improve functioning and quality of life (QoL) for chronic pain patients, but outreach of this treatment is unsatisfactory. Internet-delivery has been shown to increase treatment access but there is limited evidence regarding feasibility and effectiveness of web-based ACT for chronic pain. The aim of the study was to evaluate and iterate a novel internet-delivered ACT program, iACT, in a clinical and a self-referred sample of chronic pain patients. The intervention was developed in close collaboration with patients. To enhance learning, content was organized in short episodes to promote daily engagement in treatment. In both the clinical and self-referred samples, three critical domains were evaluated: (I) feasibility (acceptability, practicality and usage); (II) preliminary efficacy on pain interference, psychological inflexibility, value orientation, QoL, pain intensity, anxiety, insomnia and depressive symptoms; and (III) potential treatment mechanisms.

Methods: This was an open pilot study with two samples: 15 patients from a tertiary pain clinic and 24 self-referred chronic pain participants, recruited from October 2015 until January 2017. Data were collected via an online platform in free text and self-report measures, as well as through individual oral feedback. Group differences were analyzed with Chi square-, Mann-Whitney U- or -test. Preliminary efficacy and treatment mechanism data were collected via self-report and analyzed with multilevel linear modeling for repeated measures.

Results: Feasibility: patient feedback guided modifications to refine the intervention and indicated that iACT was acceptable in both samples. User insights provided input for both immediate and future actions to improve feasibility. Comprehensiveness, workability and treatment credibility were adequate in both samples. Psychologists spent on average 13.5 minutes per week per clinical patient, and 8 minutes per self-referred patient (P=0.004). Recruitment rate was 24 times faster in the self-referred sample (24 patients in 1 month, compared to 15 patients in 15 months, P<0.001) and the median distance to the clinic was 40 km in the clinical sample, and 426 km in the self-referred sample (P<0.001). Preliminary effects: post-assessments were completed by 26 participants (67%). Significant effects of time were seen from pre- to post-treatment across all outcome variables. Within group effect sizes (Cohen's ) at post-treatment ranged from small to large: pain interference (=0.64, P<0.001), psychological inflexibility (=1.43, P<0.001), value progress (=0.72, P<0.001), value obstruction (=0.42, P<0.001), physical QoL (=0.41, P=0.005), mental QoL (=67, P=0.005), insomnia (0.31, P001), depressive symptoms (=0.47, P<0.001), pain intensity (=0.78, P=0.001) and anxiety (=46, P<0.001). Improvements were sustained at 1-year follow-up. Psychological inflexibility and value progress were found to be potential treatment mechanisms.

Conclusions: The results from the present study suggests that iACT was feasible in both the clinical and the self-referred sample. Together with the positive preliminary results on all outcomes, the findings from this feasibility study pave the way for a subsequent large randomized efficacy trial.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.21037/mhealth.2020.02.02DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7327284PMC
July 2020

Olfactory Communication of Sickness Cues in Respiratory Infection.

Front Psychol 2020 9;11:1004. Epub 2020 Jun 9.

Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.

Animals detect sick conspecifics by way of body odor that enables the receiver to avoid potential infectious transmission. Human observational studies also indicate that different types of disease are associated with more or less aversive smells. In addition, body odors from otherwise healthy human individuals smell more aversive as a function of experimentally induced systemic inflammation. To investigate if naturally occurring immune activation also gives rise to perceivable olfactory changes, we collected body odor samples during two nights from individuals with a respiratory infection as well as when they were healthy. We hypothesized that independent raters would rate the body odor originating from sick individuals as smelling more aversive than when the same individuals were healthy. Even though body odor samples from sick individuals nominally smelled more intense, more disgusting, and less pleasant and healthy than the body odor from the same individuals when healthy, these effects were not statistically significant. Moreover, raters filled out three questionnaires, Perceived Vulnerability to Disease, Disgust Scale, and Health Anxiety, to assess potential associations between sickness-related personality traits and body odor perception. No such association was found. Since experimentally induced inflammation have made body odors more aversive in previous studies, we discuss whether this difference between studies is due to the level of sickness or to the type of trigger of the sickness response.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fpsyg.2020.01004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7296143PMC
June 2020

Gray Matter Volume Correlates of Sleepiness: A Voxel-Based Morphometry Study in Younger and Older Adults.

Nat Sci Sleep 2020 21;12:289-298. Epub 2020 May 21.

Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.

Background: Subjectively experienced sleepiness is a problem in society, possibly linked with gray matter (GM) volume. Given a different sleep pattern, aging may affect such associations, possibly due to shrinking brain volume.

Purpose: The purpose of the present study was to investigate the association between subjectively rated sleepiness and GM volume in thalamus, insula, hippocampus, and orbitofrontal cortex of young and older adults, after a normal night's sleep.

Methods: Eighty-four healthy individuals participated (46 aged 20-30 years, and 38 aged 65-75 years). Morphological brain data were collected in a 3T magnetic resonance imaging (MRI) scanner. Sleepiness was rated multiple times during the imaging sessions.

Results: In older, relative to younger, adults, clusters within bilateral mid-anterior insular cortex and right thalamus were negatively associated with sleepiness. Adjustment for the immediately preceding total sleep time eliminated the significant associations.

Conclusion: Self-rated momentary sleepiness in a monotonous situation appears to be negatively associated with GM volume in clusters within both thalamus and insula in older individuals, and total sleep time seems to play a role in this association. Possibly, this suggests that larger GM volume in these clusters may be protective against sleepiness in older individuals. This notion needs confirmation in further studies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2147/NSS.S240493DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7247733PMC
May 2020

Risk of transition from occasional neck/back pain to long-duration activity limiting neck/back pain: a cohort study on the influence of poor work ability and sleep disturbances in the working population in Stockholm County.

BMJ Open 2020 06 3;10(6):e033946. Epub 2020 Jun 3.

Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.

Objectives: The prevalence of neck/back pain (NBP) is high worldwide. Limited number of studies have investigated workers with occasional NBP regarding the risk of developing long-duration activity limiting NBP (LNBP). The objectives were to assess (1) the effect of poor work ability and sleep disturbances in persons with occasional NBP on the risk of LNBP, and (2) the interaction effect of these exposures.

Design: Cohort study based on three subsamples from the Stockholm Public Health Cohort.

Settings: The working population in Stockholm County.

Participants: Persons aged 18-60 years, reporting occasional NBP the past 6 months at baseline year 2010 (n=16 460).

Measures: Work ability was assessed with items from the Work Ability Index, perceived mental and/or physical work ability. Sleep disturbances were self-reported current mild/severe disturbances. The outcome in year 2014 was reporting NBP the previous 6 months, occurring ≥couple of days per week and resulting in decreased work ability/restricted other daily activities. The additive effect of having both poor work ability and sleep disturbances was modelled with a dummy variable, including both exposures. Poisson log-linear regression was used to calculate risk ratios (RRs) and 95% CIs.

Results: At follow-up, 9% had developed LNBP. Poor work ability and sleep disturbances were independent risk factors for LNBP; adjusted RR 1.7 (95% CI: 1.4 to 2.0) and 1.4 (95% CI: 1.2 to 1.5), respectively. No additive interaction was observed.

Conclusion: Workers with occasional NBP who have poor work ability and/or sleep disturbances are at risk of developing LNBP. Having both conditions does not exceed additive risk.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1136/bmjopen-2019-033946DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7282292PMC
June 2020

Comparison of bacterial lipopolysaccharide-induced sickness behavior in rodents and humans: Relevance for symptoms of anxiety and depression.

Neurosci Biobehav Rev 2020 08 17;115:15-24. Epub 2020 May 17.

Institute for Cognitive and Integrative Neuroscience, CNRS UMR 5287, University of Bordeaux, France.

Increasing evidence from animal and human studies suggests that inflammation may be involved in mood disorders. Sickness behavior and emotional changes induced by experimental inflammatory stimuli have been extensively studied in humans and rodents to better understand the mechanisms underlying inflammation-driven mood alterations. However, research in animals and humans have remained compartmentalized and a comprehensive comparison of inflammation-induced sickness and depressive-like behavior between rodents and humans is lacking. Thus, here, we highlight similarities and differences in the effects of bacterial lipopolysaccharide administration on the physiological (fever and cytokines), behavioral and emotional components of the sickness response in rodents and humans, and discuss the translational challenges involved. We also emphasize the differences between observable sickness behavior and subjective sickness reports, and advocate for the need to obtain both subjective reports and objective measurements of sickness behavior in humans. We aim to provide complementary insights for translational clinical and experimental research on inflammation-induced behavioral and emotional changes, and their relevance for mood disorders such as depression.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.neubiorev.2020.05.001DOI Listing
August 2020

People expressing olfactory and visual cues of disease are less liked.

Philos Trans R Soc Lond B Biol Sci 2020 06 20;375(1800):20190272. Epub 2020 Apr 20.

Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Sweden.

For humans, like other social animals, behaviour acts as a first line of defence against pathogens. A key component is the ability to detect subtle perceptual cues of sick conspecifics. The present study assessed the effects of endotoxin-induced olfactory and visual sickness cues on liking, as well as potential involved mechanisms. Seventy-seven participants were exposed to sick and healthy facial pictures and body odours from the same individual in a 2 × 2 factorial design while disgust-related facial electromyography (EMG) was recorded. Following exposure, participants rated their liking of the person presented. In another session, participants also answered questionnaires on perceived vulnerability to disease, disgust sensitivity and health anxiety. Lower ratings of liking were linked to both facial and body odour disease cues as main effects. Disgust, as measured by EMG, did not seem to be the mediating mechanism, but participants who perceived themselves as more prone to disgust, and as more vulnerable to disease, liked presented persons less irrespectively of their health status. Concluding, olfactory and visual sickness cues that appear already a few hours after the experimental induction of systemic inflammation have implications for human sociality and may as such be a part of a behavioural defence against disease. This article is part of the Theo Murphy meeting issue 'Olfactory communication in humans'.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1098/rstb.2019.0272DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7209934PMC
June 2020

Sleepiness as motivation: a potential mechanism for how sleep deprivation affects behavior.

Sleep 2020 Jun;43(6)

Stress Research Institute, Stockholm University, Stockholm, Sweden.

Study Objectives: To determine how sleepiness and sleep deprivation drive the motivation to engage in different behaviors.

Methods: We studied the sleepiness of 123 participants who had been randomized to sleep deprivation or normal sleep, and their willingness to engage in a range of everyday behaviors.

Results: Self-reported sleepiness was a strong predictor of the motivation to engage in sleep-preparatory behaviors such as shutting one's eyes (OR = 2.78, 95% CI: 2.19-3.52 for each step up on the Karolinska Sleepiness Scale) and resting (OR = 3.20, CI: 2.46-4.16). Sleepiness was also related to the desire to be cared for by a loved one (OR = 1.49, CI: 1.22-1.82), and preparedness to utilize monetary and energy resources to get to sleep. Conversely, increased sleepiness was associated with a decreased motivation for social and physical activities (e.g. be with friends OR = 0.71, CI: 0.61-0.82; exercise OR = 0.65, CI: 0.56-0.76). Sleep deprivation had similar effects as sleepiness on these behaviors. Neither sleepiness nor sleep deprivation had strong associations with hunger, thirst, or food preferences.

Conclusions: Our findings indicate that sleepiness is a dynamic motivational drive that promotes sleep-preparatory behaviors and competes with other drives and desired outcomes. Consequently, sleepiness may be a central mechanism by which impaired alertness, for example, due to insufficient sleep, contributes to poor quality of life and adverse health. We propose that sleepiness helps organize behaviors toward the specific goal of assuring sufficient sleep, in competition with other needs and incentives. A theoretical framework on sleepiness and its behavioral consequences are likely to improve our understanding of several disease mechanisms.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/sleep/zsz291DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7294403PMC
June 2020

Effects of cognitive behavioural therapy and return-to-work intervention for patients on sick leave due to stress-related disorders: Results from a randomized trial.

Scand J Psychol 2020 Apr 6;61(2):281-289. Epub 2019 Nov 6.

Department of Clinical Neuroscience, Division of Psychology, Karolinska Institutet, Stockholm, Sweden.

The aim of this study was to evaluate specific effects for patients with adjustment or exhaustion disorder, the Stress subgroup (n = 152), regarding symptom severity and sick leave after CBT, a return-to-work intervention (RTW-I), and a combination of them (COMBO), using data from a randomized trial. In the original study, primary care patients on sick leave (N = 211) were randomized to CBT (n = 64), RTW-I (n = 67), or COMBO (n = 80). Blinded Clinician Severity Rating (CSR) of symptoms and sick leave registry data were primary outcomes. Subgroup analyses showed that for the Stress subgroup, CBT led to greater reduction of symptoms than RTW-I posttreatment, but COMBO did not differ from CBT or RTW-I. Regarding sick leave, there was no difference between treatments in the Stress subgroup. An exploratory analysis of the treatment effects in a subgroup of patients with depression, anxiety or insomnia indicates that RTW-I reduced sick leave faster than CBT. We conclude that CBT may be promising as an effective treatment of stress and exhaustion disorder.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/sjop.12590DOI Listing
April 2020

Fatigue and sleepiness responses to experimental inflammation and exploratory analysis of the effect of baseline inflammation in healthy humans.

Brain Behav Immun 2020 01 1;83:309-314. Epub 2019 Nov 1.

Stress Research Institute, Stockholm University, Frescati Hagväg 16A, 106 91 Stockholm, Sweden; Department of Psychology, Macquarie University, North Ryde, NSW, Australia.

Inflammation is believed to be a central mechanism in the pathophysiology of fatigue. While it is likely that dynamic of the fatigue response after an immune challenge relates to the corresponding cytokine release, this lacks evidence. Although both fatigue and sleepiness are strong signals to rest, they constitute distinct symptoms which are not necessarily associated, and sleepiness in relation to inflammation has been rarely investigated. Here, we have assessed the effect of an experimental immune challenge (administration of lipopolysaccharide, LPS) on the development of both fatigue and sleepiness, and the associations between increases in cytokine concentrations, fatigue and sleepiness, in healthy volunteers. In addition, because chronic-low grade inflammation may represent a risk factor for fatigue, we tested whether higher baseline levels of inflammation result in a more pronounced development of cytokine-induced fatigue and sleepiness. Data from four experimental studies was combined, giving a total of 120 subjects (LPS N = 79, 18 (23%) women; Placebo N = 69, 12 (17%) women). Administration of LPS resulted in a stronger increase in fatigue and sleepiness compared to the placebo condition, and the development of both fatigue and sleepiness closely paralleled the cytokine responses. Individuals with stronger increases in cytokine concentrations after LPS administration also suffered more from fatigue and sleepiness (N = 75), independent of gender. However, there was no support for the hypothesis that higher baseline inflammatory markers moderated the responses in fatigue or sleepiness after an inflammatory challenge. The results demonstrate a tight connection between the acute inflammatory response and development of both fatigue and sleepiness, and motivates further investigation of the involvement of inflammation in the pathophysiology of central fatigue.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bbi.2019.10.020DOI Listing
January 2020

Predictors of outcome in guided self-help cognitive behavioural therapy for common mental disorders in primary care.

Cogn Behav Ther 2020 11 22;49(6):455-474. Epub 2019 Oct 22.

Department of Clinical Neuroscience, Division of Psychology, Karolinska Institutet , Stockholm, Sweden.

Cognitive behavioural therapy (CBT) can effectively treat common mental disorders (CMDs), but access to treatment is insufficient. Guided self-help (GSH) CBT has shown effects comparable to face-to-face CBT and may be a resource-efficient treatment alternative. However, not all patients respond to GSH. Learning more about predictors of outcome may increase knowledge regarding which patients respond to GSH. The aim of this study was to investigate predictors of outcome for GSH CBT for patients with CMDs in primary care. Consecutive patients (N = 396) with a principal disorder of depression, anxiety, insomnia or stress-related disorders were included. All patients received GSH CBT. Outcomes were remission status, reliable change and post-treatment depression ratings. Predictors investigated were clinical, demographic and therapy-related variables. Analyses were conducted using logistic and linear regression. Higher educational level predicted remission, higher quality of life ratings predicted remission and decreased depression, and higher age at onset predicted reliable change. Therapy-related variables, i.e. patient adherence to treatment and patients' and clinicians' estimation of treatment response, were all related to outcome. More large-scale studies are needed, but the present study points at the importance of therapy-related variables such as monitoring and supporting treatment adherence for an increased chance of remission.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/16506073.2019.1669701DOI Listing
November 2020

Cost-Effectiveness of Therapist-Guided Internet-Based Cognitive Behavioral Therapy for Stress-Related Disorders: Secondary Analysis of a Randomized Controlled Trial.

J Med Internet Res 2019 09 13;21(9):e14675. Epub 2019 Sep 13.

Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.

Background: Stress-related disorders are associated with significant suffering, functional impairment, and high societal costs. Internet-based cognitive behavioral therapy (ICBT) is a promising treatment for stress-related disorders but has so far not been subjected to health economic evaluation.

Objective: The objective of this study was to evaluate the cost-effectiveness and cost-utility of ICBT for patients with stress-related disorders in the form of adjustment disorder (AD) or exhaustion disorder (ED). We hypothesized that ICBT, compared with a waitlist control (WLC) group, would generate improvements at low net costs, thereby making it cost-effective.

Methods: Health economic data were obtained in tandem with a randomized controlled trial of a 12-week ICBT in which patients (N=100) were randomized to an ICBT (n=50) or a WLC (n=50) group. Health outcomes and costs were surveyed pre- and posttreatment. We calculated incremental cost-effectiveness ratios (ICERs) based on remission rates and incremental cost-utility ratios (ICURs) based on health-related quality of life. Bootstrap sampling was used to assess the uncertainty of our results.

Results: The ICER indicated that the most likely scenario was that ICBT led to higher remission rates compared with the WLC and was associated with slightly larger reductions in costs from pre- to posttreatment. ICBT had a 60% probability of being cost-effective at a willingness to pay (WTP) of US $0 and a 96% probability of being cost-effective at a WTP of US $1000. The ICUR indicated that ICBT also led to improvements in quality of life at no net societal cost. Sensitivity analyses supported the robustness of our results.

Conclusions: The results suggest that ICBT is a cost-effective treatment for patients suffering from AD or ED. Compared with no treatment, ICBT for these patients yields large effects at no or minimal societal net costs.

Trial Registration: ClinicalTrials.gov NCT02540317; https://clinicaltrials.gov/ct2/show/NCT02540317.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2196/14675DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6788336PMC
September 2019

Psychological Flexibility as a Resilience Factor in Individuals With Chronic Pain.

Front Psychol 2019 3;10:2016. Epub 2019 Sep 3.

Functional Area Medical Psychology, Functional Unit Behavior Medicine, Karolinska University Hospital, Stockholm, Sweden.

Resilience factors have been suggested as key mechanisms in the relation between symptoms and disability among individuals with chronic pain. However, there is a need to better operationalize resilience and to empirically evaluate its role and function. The present study examined psychological flexibility as a resilience factor in relation to symptoms and functioning among 252 adults with chronic pain applying for participation in a digital ACT-based self-help treatment. Participants completed measures of symptoms (pain intensity, and anxiety), functioning (pain interference and depression), as well as the hypothesized resilience factor psychological flexibility (measured as avoidance, value obstruction, and value progress). As expected, symptoms, functioning and resilience factors were significantly associated. Hierarchical linear regression analyses showed that psychological flexibility significantly contributed to the prediction of pain interference and depression when adjusting for age, pain and anxiety. Also, participants with low levels of psychological flexibility were more likely to be on sick leave. Furthermore, a series of multiple mediation analyses showed that psychological flexibility had a significant indirect effect on the relationship between symptoms and functioning. Avoidance was consistently shown to contribute to the indirect effect. Results support previous findings and suggest the importance of psychological flexibility as a resilience factor among individuals with chronic pain and anxiety.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fpsyg.2019.02016DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6734029PMC
September 2019

Processes in cognitive behavior therapy for social anxiety disorder: Predicting subsequent symptom change.

J Anxiety Disord 2019 10 27;67:102118. Epub 2019 Jul 27.

Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Osher Center for Integrative Medicine, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.

Although cognitive behavior therapy (CBT) is an effective treatment for social anxiety disorder, little is known about the processes during treatment that bring about change. The aim of this study was to investigate whether the proposed processes of change according to the cognitive model of social anxiety disorder predicted subsequent symptom reduction in CBT delivered as therapist-guided bibliotherapy. We analyzed data from patients with social anxiety disorder (N = 61) who participated in an effectiveness trial of CBT in primary care. Seven putative processes and outcome (i.e., social anxiety) were assessed on a weekly basis throughout treatment. We used linear mixed models to analyze within-person relations between processes and outcome. The results showed a unidirectional effect of reduced avoidance on subsequent decrease in social anxiety. Further, we found support for reciprocal influences between four of the proposed processes (i.e., estimated probability and cost of adverse outcome, self-focused attention, and safety behaviors) and social anxiety. The remaining two processes, (i.e., anticipatory and post-event processing) did not predict subsequent social anxiety, but were predicted by prior symptom reduction. The findings support that several of the change processes according to the cognitive model of social anxiety disorder are involved in symptom improvement.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.janxdis.2019.102118DOI Listing
October 2019

Effects of age, BMI and sex on the glial cell marker TSPO - a multicentre [C]PBR28 HRRT PET study.

Eur J Nucl Med Mol Imaging 2019 Oct 30;46(11):2329-2338. Epub 2019 Jul 30.

Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet and Stockholm County, Stockholm, Sweden.

Purpose: The purpose of this study was to investigate the effects of ageing, sex and body mass index (BMI) on translocator protein (TSPO) availability in healthy subjects using positron emission tomography (PET) and the radioligand [C]PBR28.

Methods: [C]PBR28 data from 140 healthy volunteers (72 males and 68 females; N = 78 with HAB and N = 62 MAB genotype; age range 19-80 years; BMI range 17.6-36.9) were acquired with High Resolution Research Tomograph at three centres: Karolinska Institutet (N = 53), Turku PET centre (N = 62) and Yale University PET Center (N = 25). The total volume of distribution (V) was estimated in global grey matter, frontal, temporal, occipital and parietal cortices, hippocampus and thalamus using multilinear analysis 1. The effects of age, BMI and sex on TSPO availability were investigated using linear mixed effects model, with TSPO genotype and PET centre specified as random intercepts.

Results: There were significant positive correlations between age and V in the frontal and temporal cortex. BMI showed a significant negative correlation with V in all regions. Additionally, significant differences between males and females were observed in all regions, with females showing higher V. A subgroup analysis revealed a positive correlation between V and age in all regions in male subjects, whereas age showed no effect on TSPO levels in female subjects.

Conclusion: These findings provide evidence that individual biological properties may contribute significantly to the high variation shown in TSPO binding estimates, and suggest that age, BMI and sex can be confounding factors in clinical studies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00259-019-04403-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6717599PMC
October 2019

The Challenge of the Many Choices in the Practice of Integrative Medicine.

J Altern Complement Med 2019 May;25(5):447-450

1 Osher Center for Integrative Medicine, Karolinska Institutet Stockholm, Stockholm, Sweden.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1089/acm.2019.29068.minDOI Listing
May 2019

Sleep restriction caused impaired emotional regulation without detectable brain activation changes-a functional magnetic resonance imaging study.

R Soc Open Sci 2019 Mar 27;6(3):181704. Epub 2019 Mar 27.

Department of Clinical Neuroscience, Karolinska Institutet, Nobels väg 9, Stockholm 171 77, Sweden.

Sleep restriction has been proposed to cause impaired emotional processing and emotional regulation by inhibiting top-down control from prefrontal cortex to amygdala. Intentional emotional regulation after sleep restriction has, however, never been studied using brain imaging. We aimed here to investigate the effect of partial sleep restriction on emotional regulation through cognitive reappraisal. Forty-seven young (age 20-30) and 33 older (age 65-75) participants (38/23 with complete data and successful sleep intervention) performed a cognitive reappraisal task during fMRI after a night of normal sleep and after restricted sleep (3 h). Emotional downregulation was associated with significantly increased activity in the dorsolateral prefrontal cortex ( < 0.05) and lateral orbital cortex ( < 0.05) in young, but not in older subjects. Sleep restriction was associated with a decrease in self-reported regulation success to negative stimuli ( < 0.01) and a trend towards perceiving all stimuli as less negative ( = 0.07) in young participants. No effects of sleep restriction on brain activity nor connectivity were found in either age group. In conclusion, our data do not support the idea of a prefrontal-amygdala disconnect after sleep restriction, and neural mechanisms underlying behavioural effects on emotional regulation after insufficient sleep require further investigation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1098/rsos.181704DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6458356PMC
March 2019

Mediators of Change in Cognitive Behavior Therapy for Clinical Burnout.

Behav Ther 2019 05 20;50(3):475-488. Epub 2018 Aug 20.

Karolinska Institutet.

Evidence supporting the effectiveness of cognitive behavior therapy (CBT) for stress-related illness is growing, but little is known about its mechanisms of change. The aim of this study was to investigate potential mediators of CBT for severe stress in form of clinical burnout, using an active psychological treatment as comparator. We used linear mixed models to analyze data from patients (N = 82) with clinical burnout who received either CBT or another psychological treatment in a randomized controlled trial. Potential mediators (i.e., sleep quality, behavioral activation, perceived competence, and therapeutic alliance) and outcome (i.e., symptoms of burnout) were assessed weekly during treatment. The results showed that the positive treatment effects on symptoms of burnout favoring CBT (estimated between-group d = 0.93) were mediated by improvements in sleep quality, ab = -0.017, 95% CI [-0.037, -0.002], and increase in perceived competence, ab = -0.037, 95% CI [-0.070, -0.010]. Behavioral activation, ab = -0.004 [-0.016, 0.007], and therapeutic alliance, ab = 0.002 [-0.006, 0.011], did not significantly mediate the difference in effects between the treatments. Improving sleep quality and increasing perceived competence may thus constitute important process goals in order to attain symptom reduction in CBT for clinical burnout.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.beth.2018.08.005DOI Listing
May 2019

Positivity Effect and Working Memory Performance Remains Intact in Older Adults After Sleep Deprivation.

Front Psychol 2019 22;10:605. Epub 2019 Mar 22.

Stress Research Institute, Stockholm University, Stockholm, Sweden.

Older adults perform better in tasks which include positive stimuli, referred to as the positivity effect. However, recent research suggests that the positivity effect could be attenuated when additional challenges such as stress or cognitive demands are introduced. Moreover, it is well established that older adults are relatively resilient to many of the adverse effects of sleep deprivation. Our aim was to investigate if the positivity effect in older adults is affected by one night of total sleep deprivation using an emotional working memory task. A healthy sample of 48 older adults (60-72 years) was either sleep deprived for one night ( = 24) or had a normal night's sleep ( = 24). They performed an emotional working memory -back ( = 1 and 3) task containing positive, negative and neutral pictures. Performance in terms of accuracy and reaction times was best for positive stimuli and worst for negative stimuli. This positivity effect was not altered by sleep deprivation. Results also showed that, despite significantly increased sleepiness, there was no effect of sleep deprivation on working memory performance. A working memory load × valence interaction on the reaction times revealed that the beneficial effect of positive stimuli was only present in the 1-back condition. While the positivity effect and general working memory abilities in older adults are intact after one night of sleep deprivation, increased cognitive demand attenuates the positivity effect on working memory speed.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fpsyg.2019.00605DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6440387PMC
March 2019

Emotional expressions of the sick face.

Brain Behav Immun 2019 08 3;80:286-291. Epub 2019 Apr 3.

Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.

To handle the substantial threat posed by infectious diseases, behaviors that promote avoidance of contagion are crucial. Based on the fact that sickness depresses mood and that emotional expressions reveal inner states of individuals to others, which in turn affect approach/avoidance behaviors, we hypothesized that facial expressions of emotion may play a role in sickness detection. Using an experimental model of sickness, 22 volunteers were intravenously injected with either endotoxin (lipopolysaccharide; 2 ng/kg body weight) and placebo using a randomized cross-over design. The volunteers were two hours later asked to keep a relaxed expression on their face while their facial photograph was taken. To assess the emotional expression of the sick face, 49 participants were recruited and were asked to rate the emotional expression of the facial photographs of the volunteers when sick and when healthy. Our results indicate that the emotional expression of faces changed two hours after being made temporarily sick by an endotoxin injection. Sick faces were perceived as more sick/less healthy, but also as expressing more negative emotions, such as sadness and disgust, and less happiness and surprise. The emotional expressions mediated 59.1% of the treatment-dependent change in rated health. The inclusion of physical features associated with emotional expressions to the mediation analysis supported these results. We conclude that emotional expressions may contribute to detection and avoidance of infectious individuals and thereby be part of a behavioral defense against disease.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bbi.2019.04.003DOI Listing
August 2019

The effect of a transient immune activation on subjective health perception in two placebo controlled randomised experiments.

PLoS One 2019 6;14(3):e0212313. Epub 2019 Mar 6.

Stress Research Institute, Stockholm University, Stockholm, Sweden.

Background: Patient-reported outcomes predict mortality and play increasingly important roles in care, but factors that modify central measures such as health ratings have been little investigated. Building on designated immune-to-brain pathways, we aimed to determine how a short-term induced inflammation response impacts self-reported health status.

Methods: Lipopolysaccharide injections were used to provoke acute systemic inflammatory responses in healthy men and women and were compared to placebo in two double-blind randomized experiments. In Experiment 1, 8 individuals (mean 24 years; SD = 3.7) received lipopolysaccharide 0.8 ng/kg once and placebo once in a cross-over design, and in Experiment 2, 52 individuals received either lipopolysaccharide 0.6 ng/kg or placebo once (28.6 years; SD = 7.1). Main outcomes were perceived health (general and current), sickness behaviour (like fatigue, pain and negative affect), and plasma interleukin-6, interleukin-8 and tumour necrosis factor-α, before and after injection.

Results: Compared to placebo, lipopolysaccharide lead to a deterioration in both self-rated general (Experiment 1, b = 1.88 for 0.8 ng/kg) and current health (Experiment 1 b = -3.00; and Experiment 2 b = -1.79) 1.5h after injection (p's<0.01), effects that remained after 4.5 to 5 hours (p's<0.05). The effect on current health in Experiment 2 was mediated by increased inflammation and sickness behaviour in response to lipopolysaccharide injection (β = -0.28, p = 0.01).

Conclusion: Health is drastically re-evaluated during inflammatory activation. The findings are consistent with notions that inflammation forms part of health-relevant interoceptive computations of bodily state, and hint at one mechanism as to why subjective health predicts longevity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0212313PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6402640PMC
November 2019

Sleep deprivation and its effects on communication during individual and collaborative tasks.

Sci Rep 2019 02 28;9(1):3131. Epub 2019 Feb 28.

Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.

Sleep loss has been shown to cause impairments in a number of aspects central for successful communication, ranging from poorer linguistic comprehension to alterations in speech prosody. However, the effect of sleep loss on actual communication is unknown. This study investigated how a night of sleep deprivation affected performance during multiple tasks designed to test verbal communication. Healthy participants (N = 183) spent 8-9 hours per night in bed for three nights and were then randomised to either one night of total sleep deprivation or a fourth night with 8-9 hours in bed. The following day, participants completed two tasks together with another participant: a model-building task and a word-description task. Differences in performance of these tasks were assessed alongside speaking duration, speaking volume, and speaking volume consistency. Additionally, participants individually completed a verbal fluency assessment. Performance on the model-building task was worse if the model-builder was sleep deprived, whereas sleep deprivation in the instruction-giver predicted an improvement. Word-description, verbal fluency, speech duration, speaking volume, and speaking volume consistency were not affected. The results suggest that sleep deprivation leads to changes in communicative performance during instructive tasks, while simpler word-description tasks appear resilient.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-019-39271-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6395705PMC
February 2019