Sleep disturbances and incident risk of major depressive disorder in a population-based cohort.

Sleep disturbances are well-known symptoms of major depressive disorder (MDD). However, the prospective risk of MDD in the presence of sleep disturbances in a general population-based cohort is not well known. This study investigated associations between both polysomnography (PSG)-based or subjective sleep features and incident MDD. Participants representative of the general population who had never had MDD completed sleep questionnaires (n = 2000) and/or underwent PSG (n = 717). Over 8 years' follow-up, participants completed psychiatric interviews enabling the diagnosis of MDD. Survival Cox models were used to analyze associations between sleep features and MDD incidence. A higher Epworth Sleepiness Scale and presence of insomnia symptoms were significantly associated with a higher incidence of MDD (hazard ratio [HR] [95 % confidence interval (CI)]: 1.062 [1.022-1.103], p = 0.002 and 1.437 [1.064-1.940], p = 0.018, respectively). Higher density of rapid eye movements in rapid eye movement (REM) sleep was associated with a higher incidence of MDD in men (HR 1.270 [95 % CI 1.064-1.516], p = 0.008). In women, higher delta power spectral density was associated with a lower MDD incidence (HR 0.674 [95 % CI 0.463-0.981], p = 0.039). This study confirmed the associations between subjective and objective sleep features and the incidence of MDD in a large community dwelling cohort.

Objective polysomnography-based sleep features and major depressive disorder subtypes in the general population.

Insomnia and its opposite hypersomnia are part of the diagnostic criteria for major depressive disorder (MDD). However, no study has investigated whether the postulated sleep alterations in clinical subtypes of MDD are reflected in polysomnography (PSG)-derived objective sleep measures. The objective of this study was to establish associations between the melancholic, atypical and unspecified subtypes of MDD and objective PSG-based sleep features. This cross-sectional analysis included 1820 community-dwelling individuals who underwent PSG and a semi-structured psychiatric interview to elicit diagnostic criteria for MDD and its subtypes. Adjusted robust linear regression was used to assess associations between MDD subtypes and PSG-derived objective sleep measures. Current melancholic MDD was significantly associated with decreased absolute delta power and sleep efficiency and with increased wake after sleep onset. Remitted unspecified MDD was significantly associated with increased rapid eye movements density. No other significant associations were identified. Our findings reflect that some PSG-based sleep features differed in MDD subtypes compared with no MDD. The largest number of significant differences were observed for current melancholic MDD, whereas only rapid eye movements density could represent a risk factor for MDD as it was the only sleep measure that was also associated with MDD in remitted participants.

What Role Does Sleep Play in Weight Gain in the First Semester of University?

We hypothesized that shorter sleep durations and greater variability in sleep patterns are associated with weight gain in the first semester of university. Students (N = 132) completed daily sleep diaries for 9 weeks, completed the MEQ (chronotype) and CES-D (depressed mood) at week 9, and self-reported weight/height (weeks 1 & 9). Mean and variability scores were calculated for sleep duration (TST, TSTv), bedtime (BT, BTv), and wake time (WT, WTv). An initial hierarchical regression evaluated (block 1) sex, ethnicity; (block 2) depressed mood, chronotype; (block 3) TST; (block 4) BT, WT; and (block 5; R(2) change = 0.09, p = 0.005) TSTv, BTv, WTv with weight change. A sex-by-TSTv interaction was found. A final model showed that ethnicity, TST, TSTv, and BTv accounted for 31% of the variance in weight change for males; TSTv was the most significant contributor (R(2) change = 0.21, p < 0.001). Daily variability in sleep duration contributes to males' weight gain. Further investigation needs to examine sex-specific outcomes for sleep and weight.

Sex of college students moderates associations among bedtime, time in bed, and circadian phase angle.

Sex differences in circadian rhythms have been reported with some conflicting results. The timing of sleep and length of time in bed have not been considered, however, in previous such studies. The current study has 3 major aims: (1) replicate previous studies in a large sample of young adults for sex differences in sleep patterns and dim light melatonin onset (DLMO) phase; (2) in a subsample constrained by matching across sex for bedtime and time in bed, confirm sex differences in DLMO and phase angle of DLMO to bedtime; (3) explore sex differences in the influence of sleep timing and length of time in bed on phase angle. A total of 356 first-year Brown University students (207 women) aged 17.7 to 21.4 years (mean = 18.8 years, SD = 0.4 years) were included in these analyses. Wake time was the only sleep variable that showed a sex difference. DLMO phase was earlier in women than men and phase angle wider in women than men. Shorter time in bed was associated with wider phase angle in women and men. In men, however, a 3-way interaction indicated that phase angles were influenced by both bedtime and time in bed; a complex interaction was not found for women. These analyses in a large sample of young adults on self-selected schedules confirm a sex difference in wake time, circadian phase, and the association between circadian phase and reported bedtime. A complex interaction with length of time in bed occurred for men but not women. We propose that these sex differences likely indicate fundamental differences in the biology of the sleep and circadian timing systems as well as in behavioral choices.

Reliability of a Scale Assessing Depressed Mood in the Context of Sleep.

The current study assessed the reliability of Kandel & Davies mood scale with and without sleep-related items. 178 Brown University first-year students (mean age=18.1 years; 108 females) completed online biweekly surveys after weeks 2, 6, 8, and 10 and on 2 consecutive days after weeks 4 and 12 of their first semester. The scale was examined as a 1) full 6-item scale, 2) 5-item scale excluding the sleep item, and 3) 4-item scale excluding the sleep and tired items. Intraclass correlations (ICC) values for consecutive-day assessments and 6 biweekly surveys were similar and not a function of the weeks evaluated. Total-item correlations and inter-measure correlations with the Center for Epidemiologic Studies - Depressed Mood Scale (CES-D) supported the removal of the sleep-related items from the 6-item scale. These analyses confirm the reliability of the original Kandel and Davies depressed mood scale as well as without the sleep-related items.

Correlates of insomnia in patients with social phobia: role of depression and anxiety.

The severity of insomnia and the relationships between social fear, anxiety, depression and insomnia were examined in 179 patients with social phobia. Two-thirds of our sample had insomnia. Depression, anxiety, social anxiety, and insomnia were positively correlated. General and social anxiety contributed to insomnia when accounting for depression.

Physiology of normal sleep in adolescents.

Among the many behavioral changes associated with adolescent development are later bedtimes and less sleep. This article presents an overview of healthy adolescent sleep in humans along with a review of the maturation of homeostatic (process S) and circadian (process C) processes regulating sleep. We propose that maturational changes to the homeostatic and circadian processes push adolescents toward later bedtimes, while societal demands, such as early school start times, result in a pattern of insufficient and ill-timed sleep. The implications of sleep curtailment during this developmental period are discussed.

[Objective improvement of sleep disorders in the elderly by a health education program]. / Les troubles du sommeil peuvent être objectivement améliorés chez les seniors par un programme personnalisé d'éducation à la santé

INTRODUCTION: The prevalence of sleep disorders increases with age and reaches 20 to 40% of those older than 60 years. We set up a health education program to help the elderly to improve their sleep. It includes a preliminary 9-day evaluation with a sleep diary and wrist actigraph, a day of group cognitive behavioral therapy, and a follow-up assessment, again with sleep diary and actigraph. METHODS: Of the 26 study participants (9 men and 17 women, mean age: 68+/-1 years), 14 had insomnia with night awakenings of 1 hour or longer or a sleep latency of 30 minutes or longer or both (group 1). The other 12 (group 2) also complained of insufficient sleep. RESULTS: In the weeks following cognitive behavioral therapy, group 1 improved their total sleep time by an average of 24 to 33 minutes, with reduced night-time awakenings and sleep latency and no change in their time spent in bed. Those in group 2 also increased their total sleep time by 18 to 47 minutes, by spending more time in bed and maintaining a sleep efficiency close to 88%. CONCLUSION: This study showed that cognitive behavioral therapy coupled with individual sleep evaluation improves sleep duration in elderly people who complain of insufficient sleep. These beneficial effects were accompanied by positive assessments of both subjective sleep quality and morning energy.

[Comorbidity in obsessive-compulsive disorder]. / Comorbidités des troubles obsessionnels compulsifs.

It has been identified for a long time that obsessive-compulsive disorder (OCD) coexists with other psychiatric disorders: in over 50 percent of the OCD, patients meet the criteria for at least one axis I disorder (depression, anxiety disorders, eating disorders, impulse control disorders). Depressive disorders are the most commonly co-occurring difficulties and associated with significantly higher level of impairment and distress. Eating disorders and impulse control disorders are common comorbidity in OCD. These disorders as eating disorders, body dysmorphic disorder, trichotillomania, pathological gambling, share similarities in etiology, comorbidity, clinical features and treatment. Actually the notion of a spectrum of obsessive-compulsive related disorders is suggested by numerous studies.

Preliminary observations on the effects of sleep time in a sleep restriction paradigm.

OBJECTIVE: To evaluate of the effect of 7 days of sleep restriction--with sleep placed at the beginning of night or early morning hours - on sleep variables, maintenance of wakefulness test, and serum leptin. METHODS: After screening young adults with questionnaires and actigraphy for 1 week, eight young adult males were recruited to participate in a sleep restriction study. The subjects were studied for baseline data for 2.5 days, with 8.5 h per night in bed, and then over 7 days of sleep restriction to 4 h per night with a 22:30 h bedtime for half the group and a 02:15 h bedtime for the other half. At the end of study, after one night of ad libitum sleep, subjects again had 2 days of 8.5 h in bed. Wakefulness was continuously verified and tests, including Maintenance of Wakefulness (MWT), were performed during the scheduled wake time. Blood was drawn six times throughout the 24 h of the 7th day of sleep restriction and after 2 days of the post-restriction schedule. RESULTS: There was individual variability in response to sleep restriction, but independent of group distribution, MWT was significantly affected by sleep restriction, with the early morning sleep group having less decrease in MWT score. Sleep efficiency was also better in this group, which also had shorter sleep latency. Independent of group distribution there was a greater increase in the percentage of slow wave sleep than rapid eye movement sleep, despite a clear internal variability and variability between subjects. Peak serum leptin was significantly decreased with 7 days of sleep restriction for all subjects. CONCLUSION: Sleep restriction to 4 h affected all subjects, but there were individual and group differences in MWT and sleep data. In this group of young adult males (mean age 19 years), there was a better overall adaptation to the early morning sleep, perhaps related to the general tendency in most adolescents to present some phase-delay during late teen-aged years.