Publications by authors named "Michelle Thai"

15 Publications

  • Page 1 of 1

Coordination between frontolimbic resting state connectivity and hypothalamic-pituitary-adrenal axis functioning in adolescents with and without depression.

Psychoneuroendocrinology 2021 Mar 28;125:105123. Epub 2020 Dec 28.

Psychology Department, College of Liberal Arts, University of Minnesota, Twin Cities, United States. Electronic address:

Depression is associated with abnormalities in Hypothalamic-Pituitary-Adrenal (HPA) axis functioning and neural circuitry that underlie the stress response. Resting-state functional connectivity (RSFC) between frontolimbic brain regions captures intrinsic connections that may set the stage for the rallying and regulating of the HPA axis system. This study examined the association between cortisol stress response and frontolimbic (amygdala and ventral and dorsal medial prefrontal cortex [vmPFC and dmPFC respectively]) RSFC in 88 (Age: M = 15.95, SD = 2.04; 71.60% female) adolescents with (N = 55) and without (N = 33) major depressive disorder (MDD). We collected salivary cortisol in the context of a modified Trier Social Stress Test (TSST) paradigm. Key findings were that adolescents with depression and healthy controls showed different patterns of association between amygdala and vmPFC RSFC and HPA functioning: while healthy controls showed a positive relationship between frontolimbic connectivity and cortisol levels that may indicate coordination across neural and neuroendocrine systems, adolescents with depression showed a minimal or inverse relationship, suggesting poor coordination of these systems. Results were similar when examining non-suicidal self-injury subgroups within the MDD sample. These findings suggest that the intrinsic quality of this frontolimbic connection may be related to HPA axis functioning. In MDD, inverse associations may represent a compensatory response in one system in response to dysfunction in the other. Longitudinal multilevel research, however, is needed to disentangle how stress system coordination develops in normal and pathological contexts and how these systems recover with treatment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.psyneuen.2020.105123DOI Listing
March 2021

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

Neural and Behavioral Correlates of Clinical Improvement to Ketamine in Adolescents With Treatment Resistant Depression.

Front Psychiatry 2020 18;11:820. Epub 2020 Aug 18.

Department of Psychiatry and Behavioral Sciences, School of Medicine, University of Minnesota, Twin Cities, MN, United States.

Treatment-resistant depression (TRD) is a serious problem in adolescents. Development and optimization of novel interventions for these youth will require a deeper knowledge of the neurobiology of depression. A well-established phenomenon of depression is an attention bias toward negativity and away from positivity that is evidenced behaviorally and neurally, but it is unclear how symptom reduction is related to changes to this bias. Neurobiological research using a treatment probe has promise to help discover the neural changes that accompany symptom improvement. Ketamine has utility for such research because of its known rapid and strong antidepressant effects in the context of TRD. Our previous study of six open-label ketamine infusions in 11 adolescents with TRD showed variable response, ranging from full remission, partial response, non-response, or clinical worsening. In this study, we examined the performance of these participants on Word Face Stroop (WFS) fMRI task where they indicated the valence of affective words superimposed onto either congruent or incongruent emotional faces before and after the ketamine infusions. Participants also completed a clinical assessment (including measurement of depression symptomology and anhedonia/pleasure) before and after the ketamine infusions. Following ketamine treatment, better WFS performance correlated with self-reported decreased depressive symptoms and increased pleasure. Analyses of corticolimbic, corticostriatal and default mode (DMN) networks showed that across networks, decreased activation during all conditions (congruent negative, congruent positive, incongruent negative, and incongruent positive) correlated with decreases in depressive symptoms and with increases in pleasure. These findings suggest that in adolescents with TRD, clinical improvement may require an attenuation of the negativity bias and re-tuning of these three critical neural networks to attenuate DMN and limbic regions activation and allow more efficient recruitment of the reward network. Lower activation across conditions may facilitate shifting across different salient emotional stimuli rather than getting trapped in downward negative spirals.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fpsyt.2020.00820DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7461781PMC
August 2020

Brain entropy and neurotrophic molecular markers accompanying clinical improvement after ketamine: Preliminary evidence in adolescents with treatment-resistant depression.

J Psychopharmacol 2021 Feb 9;35(2):168-177. Epub 2020 Jul 9.

Department of Psychiatry and Behavioral Sciences, Medical School, University of Minnesota, Minneapolis, USA.

Background: Current theory suggests that treatment-resistant depression (TRD) involves impaired neuroplasticity resulting in cognitive and neural rigidity, and that clinical improvement may require increasing brain flexibility and adaptability.

Aims: In this hypothesis-generating study, we sought to identify preliminary evidence of brain flexibility correlates of clinical change within the context of an open-label ketamine trial in adolescents with TRD, focusing on two promising candidate markers of neural flexibility: (a) entropy of resting-state functional magnetic resonance imaging (fMRI) signals; and (b) insulin-stimulated phosphorylation of mammalian target of rapamycin (mTOR) and glycogen synthase-3-beta (GSK3β) in peripheral blood mononuclear cells.

Methods: We collected resting-state functional magnetic resonance imaging data and blood samples from 13 adolescents with TRD before and after a series of six ketamine infusions over 2 weeks. Usable pre/post ketamine data were available from 11 adolescents for imaging and from 10 adolescents for molecular signaling. We examined correlations between treatment response and changes in the central and peripheral flexibility markers.

Results: Depression reduction correlated with increased nucleus accumbens entropy. Follow-up analyses suggested that physiological changes were associated with treatment response. In contrast to treatment non-responders (=6), responders (=5) showed greater increase in nucleus accumbens entropy after ketamine, together with greater post-treatment insulin/mTOR/GSK3β signaling.

Conclusions: These data provide preliminary evidence that changes in neural flexibility may underlie symptom relief in adolescents with TRD following ketamine. Future research with adequately powered samples is needed to confirm resting-state entropy and insulin-stimulated mTOR and GSK3β as brain flexibility markers and candidate targets for future clinical trials.

Clinical Trial Name: Ketamine in adolescents with treatment-resistant depression https://clinicaltrials.gov/ct2/show/NCT02078817 NCT02078817.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/0269881120928203DOI Listing
February 2021

Editorial: The Ups and Downs of Mind-Wandering in Adolescents.

J Am Acad Child Adolesc Psychiatry 2021 Mar 16;60(3):340-342. Epub 2020 Jun 16.

School of Medicine, University of Minnesota, Twin Cities. Electronic address:

The human brain is always active; it wanders freely during rest as well as when we lose focus during tasks. Mind-wandering encompasses spontaneous thinking, such as processing recent experiences, problem solving, and achieving insights. Understanding this unconstrained brain activity may lead to clues about the neural mechanisms of mental health problems. Brain networks implicated in mind-wandering include the default mode network (DMN), the salience network, and task-positive networks including the frontoparietal control network and dorsal attention network. Given that these networks mature during adolescence, coinciding with a time notable for the emergence of mental health problems, quantifying and examining the neural correlates of mind-wandering in adolescents with psychopathology may shed light on how the healthy and pathological brain functions and point to possible methods of intervening.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jaac.2020.06.001DOI Listing
March 2021

Transcendental meditation and hypothalamic-pituitary-adrenal axis functioning: a pilot, randomized controlled trial with young adults.

Stress 2020 01 11;23(1):105-115. Epub 2019 Sep 11.

Department of Psychiatry, University of Minnesota, Minneapolis, MN, USA.

Transcendental meditation (TM) is effective in alleviating stress and anxiety and promoting well-being. While the underlying biological mechanisms of TM are not yet fully explored, the hypothalamic-pituitary-adrenal (HPA) axis represents an index providing important clues embodying the stress system cascade. In this pilot study, young adults were randomly assigned to TM training followed by 8 weeks of meditation practice or a wait-list control condition. TM was conducted over 8 weeks. Thirty-four young adult participants were randomized; 27 participants completed the HPA outcome assessments (41% male). To assess HPA axis functioning, salivary samples to assess cortisol awakening response (CAR) that were collected in the morning, both at baseline and at week-4. Salivary cortisol in the context of a social stressor using the Trier Social Stress Test (TSST) was collected at week-8. The results indicate that participants who were randomly assigned to TM had lower awakening salivary cortisol levels and a greater drop in CAR from baseline to week-4 than the control group. There were no significant differences in HPA axis functioning in the context of the TSST. Primary limitations of this randomized controlled trial were the small sample size, the use of a wait-list as opposed to an active control, and the limited scope of HPA axis assessments. The results of this pilot study provide tentative evidence that TM may impact biological stress system functioning and suggests that this may be a worthwhile avenue to continue to examine. It will also be useful to extend these findings to a broader array of meditative and mindful practices, particularly for those who are experiencing more distress.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/10253890.2019.1656714DOI Listing
January 2020

Digital Interventions to Build a Patient Registry for Rheumatology Research.

Rheum Dis Clin North Am 2019 05;45(2):173-186

Division of Clinical Immunology & Rheumatology, University of Alabama at Birmingham, Faculty Office Tower, 510 20th Street South #834, Birmingham, AL 35294, USA.

This article aims to describe key issues, processes, and outcomes related to development of a patient registry for rheumatology research using a digital platform where patients track useful data about their condition for their own use while contributing to research. Digital interventions are effective to build a patient research registry for people with rheumatoid arthritis and other rheumatic and musculoskeletal diseases. ArthritisPower provides evidence of the value of digital interventions to build community support for research and to transform patient engagement and patient-generated data capture.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.rdc.2019.01.009DOI Listing
May 2019

Digital Interventions to Build a Patient Registry for Rheumatology Research.

Rheum Dis Clin North Am 2019 05;45(2):173-186

Division of Clinical Immunology & Rheumatology, University of Alabama at Birmingham, Faculty Office Tower, 510 20th Street South #834, Birmingham, AL 35294, USA.

This article aims to describe key issues, processes, and outcomes related to development of a patient registry for rheumatology research using a digital platform where patients track useful data about their condition for their own use while contributing to research. Digital interventions are effective to build a patient research registry for people with rheumatoid arthritis and other rheumatic and musculoskeletal diseases. ArthritisPower provides evidence of the value of digital interventions to build community support for research and to transform patient engagement and patient-generated data capture.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.rdc.2019.01.009DOI Listing
May 2019

Cortisol Awakening Response, Internalizing Symptoms, and Life Satisfaction in Emerging Adults.

Int J Mol Sci 2017 Nov 27;18(12). Epub 2017 Nov 27.

Department of Psychology, College of Liberal Arts, University of Minnesota, Minneapolis, MN 55455, USA.

The cortisol awakening response (CAR) has been associated with depression and a broader range of internalizing problems. Emerging adulthood is characterized by numerous stressful transitional life events. Furthermore, the functioning of the neurobiological stress system changes across development. These considerations underscore the importance of evaluating the physiological stress system in emerging adults in identifying the extent to which cortisol levels vary with risk and protective factors for mental health. The present study evaluated the association between internalizing symptoms and perceived life satisfaction with CAR in 32 young adults. Three saliva samples were collected to measure cortisol levels upon awakening and participants completed the Depression Anxiety Stress Scale (DASS) and Satisfaction with Life Scale (SWLS). Results show a significant positive correlation between area under the curve for CAR with internalizing symptoms (DASS total) and the DASS-depression subscale, but not with life satisfaction. Study limitations, implications, and future directions for these finding were discussed.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijms18122501DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5751104PMC
November 2017

Neural and neuroendocrine predictors of pharmacological treatment response in adolescents with depression: A preliminary study.

Prog Neuropsychopharmacol Biol Psychiatry 2018 Feb 1;81:194-202. Epub 2017 Nov 1.

Department of Psychiatry, University of Minnesota, Minneapolis, MN, United States.

Objective: Typically, about 30 to 50% of adolescents with depression fail to respond to evidence-based treatments, including antidepressant medications such as selective serotonin reuptake inhibitors (SSRIs). Efforts for identifying predictors and moderators of treatment response are needed to begin to address critical questions relevant to personalized care in adolescent depression. In this pilot study, we aim to identify biological predictors of response to antidepressant treatment.

Method: We used a multiple levels of analysis approach to evaluate threat system functioning (fronto-limbic system and the associated hormonal cascade) to determine if key biological indexes at baseline could predict improvement in depressive symptoms after eight weeks of antidepressant treatment in adolescents with depression.

Results: Neural predictors of favorable treatment response included lower amygdala connectivity with left supplementary motor area and with right precentral gyrus, and greater amygdala connectivity with right central opercular cortex and Heschl's gyrus connectivity during rest. During an emotion task, neural predictors of treatment response were greater activation of the bilateral anterior cingulate cortex and left medial frontal gyrus. Additionally, different patterns of salivary cortisol obtained in the context of a modified Trier Social Stress Test were associated with those whose depressive symptoms remitted as compared to those whose symptoms persisted.

Conclusions: This approach shows significant promise for identifying predictors of treatment response in adolescents with depression. Future work is needed that incorporates sufficiently powered, randomized control trials to provide the basis by which both predictors and moderators of treatment response are identified. The hope is that this work will inform the development of methods that can guide clinician decision-making in assigning beneficial treatments for adolescents who are suffering from depression.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.pnpbp.2017.10.015DOI Listing
February 2018

Network-targeted cerebellar transcranial magnetic stimulation improves attentional control.

Neuroimage 2017 08 8;156:190-198. Epub 2017 May 8.

Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, United States.

Developing non-invasive brain stimulation interventions to improve attentional control is extremely relevant to a variety of neurological and psychiatric populations, yet few studies have identified reliable biomarkers that can be readily modified to improve attentional control. One potential biomarker of attention is functional connectivity in the core cortical network supporting attention - the dorsal attention network (DAN). We used a network-targeted cerebellar transcranial magnetic stimulation (TMS) procedure, intended to enhance cortical functional connectivity in the DAN. Specifically, in healthy young adults we administered intermittent theta burst TMS (iTBS) to the midline cerebellar node of the DAN and, as a control, the right cerebellar node of the default mode network (DMN). These cerebellar targets were localized using individual resting-state fMRI scans. Participants completed assessments of both sustained (gradual onset continuous performance task, gradCPT) and transient attentional control (attentional blink) immediately before and after stimulation, in two sessions (cerebellar DAN and DMN). Following cerebellar DAN stimulation, participants had significantly fewer attentional lapses (lower commission error rates) on the gradCPT. In contrast, stimulation to the cerebellar DMN did not affect gradCPT performance. Further, in the DAN condition, individuals with worse baseline gradCPT performance showed the greatest enhancement in gradCPT performance. These results suggest that temporarily increasing functional connectivity in the DAN via network-targeted cerebellar stimulation can enhance sustained attention, particularly in those with poor baseline performance. With regard to transient attention, TMS stimulation improved attentional blink performance across both stimulation sites, suggesting increasing functional connectivity in both networks can enhance this aspect of attention. These findings have important implications for intervention applications of TMS and theoretical models of functional connectivity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.neuroimage.2017.05.011DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5973536PMC
August 2017

Trauma Sequelae are Uniquely Associated with Components of Self-Reported Sleep Dysfunction in OEF/OIF/OND Veterans.

Behav Sleep Med 2018 Jan-Feb;16(1):38-63. Epub 2016 May 16.

b Geriatric Research Education and Clinical Center , Boston Division VA Healthcare System , Boston , Massachusetts , USA.

While the associations between psychological distress (e.g., posttraumatic stress disorder [PTSD], depression) and sleep dysfunction have been demonstrated in trauma-exposed populations, studies have not fully explored the associations between sleep dysfunction and the wide range of common physical and physiological changes that can occur after trauma exposure (e.g., pain, cardiometabolic risk factors). We aimed to clarify the unique associations of psychological and physical trauma sequelae with different aspects of self-reported sleep dysfunction. A comprehensive psychological and physical examination was administered to 283 combat-deployed trauma-exposed Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn (OEF/OIF/OND) veterans. The Pittsburgh Sleep Quality Index (PSQI) and PSQI Addendum for PSTD (PSQI-A) were administered along with measures of PTSD, depression, anxiety, pain, traumatic brain injury, alcohol use, nicotine dependence, and cardiometabolic symptoms. We first performed a confirmatory factor analysis of the PSQI and then conducted regressions with the separate PSQI factors as well as the PSQI-A to identify unique associations between trauma-related measures and the separate aspects of sleep. We found that the PSQI global score was composed of three factors: Sleep Efficiency (sleep efficiency/sleep duration), Perceived Sleep Quality (sleep quality/sleep latency/sleep medication) and Daily Disturbances (sleep disturbances/daytime dysfunction). Linear regressions demonstrated that PTSD symptoms were uniquely associated with the PSQI global score and all three factors, as well as the PSQI-A. For the other psychological distress variables, anxiety was independently associated with PSQI global as well as Sleep Efficiency, Perceived Sleep Quality, and PSQI-A, whereas depression was uniquely associated with Daily Disturbances and PSQI-A. Notably, cardiometabolic symptoms explained independent variance in PSQI global and Sleep Efficiency. These findings help lay the groundwork for further investigations of the mechanisms of sleep dysfunction in trauma-exposed individuals and may help in the development of more effective, individualized treatments.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/15402002.2016.1173550DOI Listing
December 2017

Superiority of pictorial versus verbal presentation and initial exposure in the P300-based, complex trial protocol for concealed memory detection.

Appl Psychophysiol Biofeedback 2015 Jun;40(2):61-73

Department of Psychology, Institute for Neuroscience, Northwestern University, Evanston, IL, USA,

Two mock guilty groups had either pictorial or verbal initial exposure to crime items (probes) on which they were told they would later be tested. Then each subject was tested in two sessions on two successive days with both verbal and pictorial presentation, one test modality per session/day. The three dependent variables analyzed were three different estimates of the same basic measurement: the difference between P300s evoked by key (probe) and irrelevant stimuli. All three indexes were significantly increased more by both initial pictorial exposure, as well as by pictorial presentation modality, than by verbal exposure and presentation. We saw no main effect of exposure-presentation modality congruence, as congruence interacted with exposure: The largest probe-irrelevant differences were evoked by congruent pictorial exposure and presentation modality, and the smallest by congruent verbal exposure and presentation modality.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10484-015-9275-zDOI Listing
June 2015

Frontal eye field involvement in sustaining visual attention: evidence from transcranial magnetic stimulation.

Neuroimage 2015 May 3;111:542-8. Epub 2015 Feb 3.

Boston Attention and Learning Laboratory & Neuroimaging Research for Veterans Center (NeRVe), Veterans Administration, Boston Healthcare System, Boston, MA 02130, USA; Department of Medicine, Harvard Medical School, Boston, MA 02115, USA.

The frontal eye field (FEF), particularly the right FEF, is broadly implicated in top-down control of transient acts of attention, but less is known about its involvement in sustained attention. Although neuroimaging studies of sustained attention tasks commonly find FEF activation, it is unclear how this region contributes to moment-to-moment fluctuations in sustained performance. We sought to determine if the FEF plays a critical role in sustained attention, and if that role differs between periods of worse performance (out-of-the-zone) and periods of better performance (in-the-zone). We used offline 1 Hz repetitive transcranial magnetic stimulation (TMS) to temporarily attenuate either right or left FEF excitability while participants performed a go/no-go sustained attention task (the gradual onset continuous performance task). The results demonstrate that following TMS to the right FEF, sustained attention during in-the-zone periods significantly worsened both in terms of lower accuracy and increased reaction time variability. In contrast, applying TMS to the left FEF did not significantly affect accuracy or variability. These results demonstrate that the right FEF plays a crucial role in supporting optimal sustained attention.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.neuroimage.2015.01.044DOI Listing
May 2015