Ph.D., Stanford University, Psychology
Though poorly defined, hypersomnia is associated with negative health outcomes and new-onset and recurrence of psychiatric illness. Lack of definition impedes generalizability across studies. The present research clarifies hypersomnia diagnoses in bipolar disorder by exploring possible subgroups and their relationship to prospective sleep data and relapse into mood episodes.A community sample of 159 adults (aged 18-70 years) with bipolar spectrum diagnoses, euthymic at study entry, was included. Self-report inventories and clinician-administered interviews determined features of hypersomnia. Participants completed sleep diaries and wore wrist actigraphs at home to obtain prospective sleep data. Approximately 7 months later, psychiatric status was reassessed. Factor analysis and latent profile analysis explored empirical groupings within hypersomnia diagnoses.Factor analyses confirmed two separate subtypes of hypersomnia ('long sleep' and 'excessive sleepiness') that were uncorrelated. Latent profile analyses suggested a four-class solution, with 'long sleep' and 'excessive sleepiness' again representing two separate classes. Prospective sleep data suggested that the sleep of 'long sleepers' is characterized by a long time in bed, not long sleep duration. Longitudinal assessment suggested that 'excessive sleepiness' at baseline predicted mania/hypomania relapse.This study is the largest of hypersomnia to include objective sleep measurement, and refines our understanding of classification, characterization and associated morbidity. Hypersomnia appears to be comprised of two separate subgroups: long sleep and excessive sleepiness. Long sleep is characterized primarily by long bedrest duration. Excessive sleepiness is not associated with longer sleep or bedrest, but predicts relapse to mania/hypomania. Understanding these entities has important research and treatment implications.
View details for DOI 10.1017/S0033291714002918
View details for Web of Science ID 000354035000017
View details for PubMedID 25515854
Dysregulated affect is a hallmark feature of acute episodes of bipolar disorder (BD) and persists during inter-episode periods. Its contribution to course of illness is not yet known. The present report examines the prospective influence of inter-episode affect dysregulation on symptoms and functional impairment in BD.Twenty-seven participants diagnosed with inter-episode bipolar I disorder completed daily measures of negative and positive affect for 49 days (±8 days) while they remained inter-episode. One month following this daily assessment period, symptom severity interviews and a measure of functional impairment were administered by telephone.More intense negative affect and positive affect during the inter-episode period were associated with higher depressive, but not manic, symptoms at the one-month follow-up assessment. More intense and unstable negative affect, and more unstable positive affect, during the inter-episode period were associated with greater impairment in home and work functioning at the follow-up assessment. All associations remained significant after controlling for concurrent symptom levels.The findings need to be confirmed in larger samples with longer follow-up periods. A more comprehensive assessment of functional impairment is also warranted.The findings suggest that a persistent affective dysregulation between episodes of BD may be an important predictor of depression and functional impairment. Monitoring daily affect during inter-episode periods could allow for a more timely application of interventions that aim to prevent or reduce depressive symptoms and improve functioning for individuals with BD.
View details for DOI 10.1016/j.jbtep.2014.07.005
View details for Web of Science ID 000346625200003
View details for PubMedID 25164093
To evaluate the relative role of psychopathology in the relationship between physical activity and sleep, the present study investigated the day-to-day relationship between physical activity and sleep in individuals without a psychiatric disorder and individuals with bipolar disorder using a longitudinal, naturalistic design.Participants in two groups-a healthy group with no psychiatric illness (N=36) and an inter-episode bipolar disorder group (N=32)- were studied over a two-month period. Physical health was assessed by the SF-36. Daily subjective and objective measures of physical activity and sleep were collected. A total of 6,670 physical activity measurements and 6,548 sleep measurements were logged.The bipolar disorder group exhibited poorer physical health on the SF-36 and more sleep disturbance relative to the healthy group. No group differences were found in physical activity, nor in models examining the relationship between physical activity and sleep. Hierarchical linear models indicated that for every standard deviation increase in sleep disturbance (i.e., increased total wake time), there was a three percent decrease in subsequent day physical activity, in both the healthy and bipolar groups. Increased physical activity was associated with improved sleep for participants who reported greater average sleep disturbance.The results for all participants in the study suggest that reduced physical activity and sleep difficulties may be mutually maintaining processes, particularly for individuals who suffer from poor sleep. Findings also raise the potential importance of targeting physical activity and sleep concurrently in interventions aimed at improving physical and mental health.
View details for DOI 10.1016/j.mhpa.2014.05.003
View details for Web of Science ID 000348615000010
BACKGROUND: Exposure to life stress is known to adversely impact the course of bipolar disorder. Few studies have disentangled the effects of multiple types of stressors on the longitudinal course of bipolar I disorder. This study examines whether severity of chronic stressors and exposure to trauma are prospectively associated with course of illness among bipolar patients. Method One hundred and thirty-one participants diagnosed with bipolar I disorder were recruited through treatment centers, support groups and community advertisements. Severity of chronic stressors and exposure to trauma were assessed at study entry with in-person interviews using the Bedford College Life Event and Difficulty Schedule (LEDS). Course of illness was assessed by monthly interviews conducted over the course of 24 months (over 3000 assessments). RESULTS: Trauma exposure was related to more severe interpersonal chronic stressors. Multiple regression models provided evidence that severity of overall chronic stressors predicted depressive but not manic symptoms, accounting for 7.5% of explained variance. CONCLUSIONS: Overall chronic stressors seem to be an important determinant of depressive symptoms within bipolar disorder, highlighting the importance of studying multiple forms of life stress.
View details for DOI 10.1017/S0033291713000147
View details for Web of Science ID 000326944900011
View details for PubMedID 23419615
Disturbances in sleep and affect are prominent features of bipolar disorder, even during interepisode periods. Few longitudinal studies have prospectively examined the relationship between naturally occurring sleep and affect, and no studies to date have done so during interepisode periods of bipolar disorder and using the entire set of "gold standard" sleep parameters. Participants diagnosed with bipolar I disorder who were interepisode (n = 32) and healthy controls (n = 36) completed diagnostic and symptom severity interviews, and a daily sleep and affect diary, as well as an actigraphy sleep assessment, for eight weeks (M = 54 days, ± 8 days). Mutual information analysis was used to assess the degree of statistical dependence, or coupling, between time series data of sleep and affect. As measured by actigraphy, longer sleep onset latency was coupled with higher negative affect more strongly in the bipolar group than in the control group. As measured by sleep diary, longer wakefulness after sleep onset and lower sleep efficiency were coupled with higher negative affect significantly more strongly in the bipolar group than in the control group. By contrast, there were no significant differences between groups in the degree of coupling between any measures of sleep and positive affect. Findings support the coupling of sleep disturbance and negative affect during interepisode bipolar disorder. Ongoing monitoring of sleep-affect coupling may provide an important target for intervention in bipolar disorder.
View details for DOI 10.1037/a0028233
View details for Web of Science ID 000311527700007
View details for PubMedID 22845651
This study focused on social support and social strain and their cross-sectional associations with instabilities in sleep and social rhythms in inter-episode bipolar disorder (BD).Thirty-five adults diagnosed with inter-episode BD type I and 38 healthy controls completed measures of perceived social support and social strain. Group differences in support and strain were examined. Within the BD group, instabilities in sleep and social rhythms were assessed with 28 days of daily diary and actigraphy. Correlation and regression analyses were used to examine cross-sectional and prospective associations between social support, social strain, instabilities in sleep and social rhythms, and mood symptoms.The BD group reported lower social support and higher social strain than the control group. Additionally, social strain was positively correlated with manic and depressive symptoms in the BD group. Furthermore, there was a cross-sectional association between social support and more stable sleep on actigraphy in the BD group, although social support did not predict future sleep instability.These results indicate that inter-episode BD is associated with deficient social support and elevated social strain compared to controls, and that this may be due to persistent inter-episode mood symptoms. Social strain may be particularly important given its association with manic and depressive symptoms. The results also raise the possibility that sleep instability is related to poor social support in BD.
View details for DOI 10.1111/j.1399-5618.2012.01049.x
View details for Web of Science ID 000308286800006
View details for PubMedID 22862999
View details for DOI 10.1093/oxfordhb/9780195376203.013.0010
This study used a comprehensive, interview-based measure of life stress to assess the role of different types of stress in predicting first onset of psychiatric disorders among daughters of depressed (n = 22) mothers and healthy (n = 22) mothers. Several types of stress were assessed: Chronic interpersonal stress, chronic non-interpersonal stress, episodic dependent (i.e., self-generated) interpersonal stress, episodic dependent non-interpersonal stress, episodic independent interpersonal stress, and episodic independent non-interpersonal stress. Daughters (ages 9-14) were recruited to have no clinically significant symptoms upon entry (T1). By a 30-month follow-up assessment (T2), 45% of the daughters of depressed mothers, but none of the daughters of healthy mothers, had developed a psychiatric disorder. Overall, daughters of depressed mothers were exposed to more severe chronic interpersonal and non-interpersonal stress than were daughters of healthy mothers. Further, daughters of depressed mothers who developed a psychiatric disorder by T2 were exposed to more severe chronic non-interpersonal stress and episodic dependent stress than were daughters of depressed mothers who remained healthy. We discuss the implications of these findings in the context of a stress-generation model for the intergenerational transmission of psychiatric risk among children of depressed mothers.
View details for DOI 10.1016/j.jpsychires.2011.03.016
View details for Web of Science ID 000292667900001
View details for PubMedID 21524424
Although gender differences in rates of internalizing disorders, particularly depression, are well documented, the causes of these differences are not well understood. One influential hypothesis [Cutler & Nolen-Hoeksema, Sex Roles (1991), 24, 425-438] proposes that higher rates of depression in females compared to males may be partially attributable to gender differences in the effects of childhood sexual abuse. The present study has evaluated this possibility by reviewing evidence for gender moderating the effects of childhood victimization on psychiatric outcomes.Literature search using PsycINFO and Medline, applying the following inclusion criteria: publication from 1996 to 2006, community-based sampling, adequate male-to-female sample ratio, use of clearly defined psychiatric outcomes, and a statistical test of gender differences in the effects of childhood victimization on psychiatric outcomes.Thirty studies met inclusion criteria. Overall, the results were mixed. Nearly half of all studies find no gender differences. In studies that do observe gender differences, victimization tends to be associated with higher psychiatric risk in females in studies with adult samples, whereas in samples of youth, victimization tends to be associated with higher psychiatric risk in males. With respect to outcome, when gender differences were observed, outcomes were distributed across both internalizing and externalizing categories for both genders.The gender differences in prevalence rates of internalizing disorders, such as depression, do not appear to be attributable to differential effects of childhood victimization.
View details for DOI 10.1017/S0033291708003000
View details for Web of Science ID 000259654300001
View details for PubMedID 18387212
View details for Web of Science ID 000220712100007