Latent structure of EEG sleep variables in depressed and control subjects: descriptions and clinical correlates

REM parameters in drug-free major depressive disorder: A systematic review and meta-analysis

Previous studies revealed that rapid eye movement (REM) parameters, such as REM latency (RL) and REM density (RD) could be used as electrophysiological markers of depression. Yet these finding should be re-tested in a comorbid-free and drug-free sample. The present systematic review and meta-analysis was conducted to investigate whether drug-free and comorbid-free patients with unipolar depression differentiate from controls with respect to the RL and RD. The PubMed and Web of Science databases were screened from inception to 23 January 2023 for case-control studies comparing RL and RD of patients with unipolar depression and controls. The primary outcome was the standard mean difference. The data were fitted with a random-effects model. Meta-regressions were conducted to investigate patient characteristics and effect size. Publication bias assessment was checked by Egger's Regression and funnel plot asymmetry. Among 43 articles accepted as eligible, 46 RL and 22 RD measurements were included in the meta-analysis. The results indicated shortened RL and increased RD in the patient group than controls. Neither Egger's regression nor funnel plot asymmetry were significant for publication bias. In conclusion, our results tested within drug-free and comorbid-free samples are in line with the literature.

The relationship between the HDRS insomnia items and polysomnographic (PSG) measures in individuals with treatment-resistant depression

The Hamilton Depression Rating Scale (HDRS), which includes several insomnia-related items, is potentially valuable in evaluating both depressive and sleep symptoms. However, the HDRS insomnia items have not been fully assessed by objective measures. This study compared the three HDRS insomnia items (Early, Middle, and Late) with the corresponding objective polysomnography (PSG) measures of Sleep Latency (SL), middle wakefulness, and late wakefulness. The study used HDRS and PSG data from 130 baseline nights, drawn from 80 participants enrolled in clinical trials for treatment-resistant depression (TRD). Mixed models evaluated the relationship between the HDRS and PSG, and primary analyses examined the Early, Middle, and Late Insomnia HDRS items and the PSG variables SL and Waking After Sleep Onset (WASO). To approximate the Middle and Late HDRS Insomnia items more closely, WASO was divided into WASO before 4:00 a.m. (waking between Sleep Onset and 0400 h) and WASO after 4:00 a.m. (waking between 0400 h and 0700 h). Secondary analyses included summed HDRS Global Insomnia score. HDRS Early and Late Insomnia items predicted objective PSG measures of early and late wakefulness. For Early Insomnia, each additional point in severity was associated with 61% [95%CI: 35%, 93%] longer SL. For Late Insomnia, each additional point was associated with a 35% [95% CI: 13%, 63%] increase in WASO after 4:00 a.m. Middle Insomnia was marginally related to WASO before 4:00 a.m. HDRS Early and Late Insomnia items may thus provide an index of wakefulness in TRD and help monitor treatment response when objective measures such as PSG are not feasible. CLINICAL TRIALS IDENTIFIER: www.clinicaltrials.gov (NCT01204918, NCT00054704, NCT00088699).

Multidimensional sleep health domains in older men and women: an actigraphy factor analysis

The multidimensional sleep health framework emphasizes that sleep can be characterized across several domains, with implications for developing novel sleep treatments and improved prediction and health screening. However, empirical evidence regarding the domains and representative measures that exist in actigraphy-assessed sleep is lacking. We aimed to establish these domains and representative measures in older adults by examining the factor structure of 28 actigraphy-derived sleep measures from 2,841 older men from the Osteoporotic Fractures in Men Sleep Study and, separately, from 2,719 older women from the Study of Osteoporotic Fractures. Measures included means and standard deviations of actigraphy summary measures and estimates from extended cosine models of the raw actigraphy data. Exploratory factor analyses revealed the same five factors in both sexes: Timing (e.g. mean midpoint from sleep onset to wake-up), Efficiency (e.g. mean sleep efficiency), Duration (e.g. mean minutes from sleep onset to wake-up), Sleepiness/Wakefulness (e.g. mean minutes napping and amplitude of rhythm), and Regularity (e.g. standard deviation of the midpoint). Within each sex, confirmatory factor analyses confirmed the one-factor structure of each factor and the entire five-factor structure (Comparative Fit Index and Tucker-Lewis Index ≥ 0.95; Root Mean Square Error of Approximation 0.08-0.38). Correlation magnitudes among factors ranged from 0.01 to 0.34. These findings demonstrate the validity of conceptualizing actigraphy sleep as multidimensional, provide a framework for selecting sleep health domains and representative measures, and suggest targets for behavioral interventions. Similar analyses should be performed with additional measures of rhythmicity, other age ranges, and more racially/ethnically diverse samples.

The Relationship Between Childhood Trauma and Poor Sleep Health in Adulthood

OBJECTIVE

Childhood trauma has been related to adverse behavioral, mental, and health outcomes later in life. Sleep may be a potential mechanism through which childhood trauma is related to adverse health. The current retrospective study aimed to characterize the relationship between childhood trauma exposure and sleep health, a novel multidimensional measure of sleep.

METHODS

Participants (N = 161; mean [standard deviation] age = 59.85 [9.06] years; 67.7% female) retrospectively reported trauma exposure using the Trauma History Questionnaire. Childhood trauma was defined as the number of reported traumatic events before 18 years of age. Trauma exposure after 18 years of age and across the life-span was also recorded. Sleep health was derived both from diary- and actigraphy-assessed measures of sleep regularity, timing, efficiency, and duration, subjective sleep satisfaction, and daytime sleepiness from the Epworth Sleepiness Scale. The relationships between childhood trauma exposure and sleep health were examined using hierarchical linear regression, controlling for relevant covariates.

RESULTS

In unadjusted models, a greater number of childhood trauma exposures were associated with poorer diary- and actigraphy-measured sleep health in adulthood. After adjustment for current stress, depression history, and other sociodemographic covariates, greater childhood trauma remained significantly associated with poorer sleep health (diary: β = -0.20, ΔR = 0.032; actigraphy: β = -0.19, ΔR = 0.027). Trauma exposure after 18 years of age and across the life-span did not relate to diary- or actigraphy-based sleep health.

CONCLUSIONS

Childhood trauma may affect sleep health in adulthood. These findings align with the growing body of evidence linking childhood trauma to adverse health outcomes later in life.

Nighttime heart rate predicts response to depression treatment in patients with coronary heart disease

BACKGROUND

Previous studies suggest that patients with coronary heart disease (CHD) who do not respond to treatment for depression are at higher risk of mortality than are treatment responders. The purpose of this study was to determine whether elevated nighttime heart rate (HR) and low heart rate variability (HRV), both of which have been associated with depression and with cardiac events in patients with CHD, predict poor response to depression treatment in patients with CHD.

METHODS

Patients with stable CHD and a current major depressive episode completed 24h ambulatory ECG monitoring and were then treated for up to 16 weeks with cognitive behavior therapy (CBT), either alone or in combination with an antidepressant. Pre-treatment HR and HRV were calculated for 124 patients who had continuous ECG from early evening to mid-morning.

RESULTS

Following treatment, 64 of the 124 patients (52%) met study criteria for remission (Hamilton Rating Scale for Depression score≤7). Prior to treatment, non-remitters had higher nighttime HR (p=0.03) and lower nighttime HRV (p=0.01) than did the remitters, even after adjusting for potential confounds.

LIMITATIONS

Polysomnography would have provided information about objective sleep characteristics and sleep disorders. More CBT sessions and higher doses of antidepressants may have resulted in more participants in remission.

CONCLUSIONS

High nighttime HR and low nighttime HRV predict a poor response to treatment of major depression in patients with stable CHD. These findings may help explain why patients with CHD who do not respond to treatment are at higher risk for mortality.

Decreased delta sleep ratio and elevated alpha power predict vulnerability to depression during interferon-alpha treatment

OBJECTIVE

Although poor sleep accompanies depression, it is unknown which specific sleep abnormalities precede depression. This is similarly the case for depression developing during interferon-α (IFN-α) therapy. Because vulnerability becomes evident in those who slept poorly before IFN-α, we prospectively determined which specific aspect of sleep could predict subsequent depression.

METHODS

Two nights of polysomnography with quantitative electroencephalogram (EEG) were obtained in 24 adult, euthymic subjects--all subsequently treated with IFN-α for hepatitis C. Every 2 weeks, a Beck Depression Inventory-II (BDI-II) score was obtained, and the maximal increase in BDI-II from pre-treatment baseline--excluding the sleep question--was determined.

RESULTS

The delta sleep ratio (DSR; an index of early-night restorative delta power) was inversely associated with BDI-II increases (p<0.01), as was elevated alpha power (8-12 Hz; p<0.001). Both delta (0.5-4 Hz) and alpha power exhibited high between-night correlations (r=0.83 and 0.92, respectively). In mixed-effect repeated-measure analyses, there was an interaction between alpha power and DSR (p<0.001)--subjects with low alpha power and elevated DSR were resilient to developing depression. Most other sleep parameters--including total sleep time and percentage of time in slow wave sleep--were not associated with subsequent changes in depression.

CONCLUSIONS

Both high DSR and low alpha power may be specific indices of resilience. As most other aspects of sleep were not associated with resilience or vulnerability, sleep interventions to prevent depression may need to specifically target these specific sleep parameters.

Nocturnal patterns of heart rate and the risk of mortality after acute myocardial infarction

BACKGROUND

The purposes of this study were to identify nocturnal patterns of heart rate (HR) in depressed and nondepressed patients after an acute myocardial infarction (MI) and to determine which patterns, if any, are associated with all-cause mortality or recurrent infarction.

METHODS

Functional data analysis and model-based clustering methods were used to identify nocturnal HR patterns in 245 depressed and 247 nondepressed patients with a recent MI. All-cause mortality and recurrent infarctions were ascertained over a median follow-up of 24 months.

RESULTS

Three HR activity patterns were identified. In the first, HR gradually declined during the nighttime and increased the next morning. The second pattern was similar, but with a higher overall HR during the recording interval. The third showed almost no decrease in HR at night (ie, "nondipping"). All-cause mortality was higher among patients with pattern 3 than pattern 1 (P = .007), and the combined end point of recurrent MI or all-cause mortality was higher in pattern 3 than pattern 2 (P = .05). Patterns 2 and 3 were more common in the depressed than in the nondepressed patients.

CONCLUSIONS

The nondipping nocturnal HR independently predicts all-cause mortality and recurrent MI. Future studies should examine the underlying causes of nondipping nocturnal HR and its association with depression and investigate the effects of treatment on survival.

The status of sleep abnormalities as a diagnostic test for major depressive disorder

BACKGROUND

Psychiatry lags other fields in development of diagnostic tests.

METHODS

A literature review and meta-analysis was conducted to ascertain if polysomnographic abnormalities (REM density, REM latency, sleep efficiency, slow wave sleep, stage 1 and stage 2 sleep) warrant additional effort to develop them into a clinical diagnostic test for major depressive disorder (MDD). The 31 publications meeting inclusion criteria were then classified into one of three progressive steps using guidelines for evaluating the clinical usefulness of a diagnostic test.

RESULTS

Most of the abnormalities found in MDD patients, when compared to healthy controls, occurred in the expected direction with moderate effect sizes but with substantial publication bias and heterogeneity. Eleven studies compared abnormalities in MDD to other psychiatric disorders (step 2a), and four studies provided data on the sensitivity or specificity of the findings in differentiating among the psychiatric disorders that frequently appear on the same differential diagnostic list as MDD (step 2b). No multicenter trial has been conducted prospectively to test the clinical utility of the diagnostic test (step 3).

LIMITATIONS

Only published articles in the English language were used.

CONCLUSIONS

Sleep studies for the detection of MDD appear replicable with a moderate effect size. However, additional step 1 studies are needed to define the sensitivity and specificity. The heterogeneity of sleep recording, scoring techniques, and MDD must also be addressed.

Sleep phenotyping in a mouse model of extreme trait anxiety

Background

There is accumulating evidence that anxiety impairs sleep. However, due to high sleep variability in anxiety disorders, it has been difficult to state particular changes in sleep parameters caused by anxiety. Sleep profiling in an animal model with extremely high vs. low levels of trait anxiety might serve to further define sleep patterns associated with this psychopathology.

Methodology/Principal Findings

Sleep-wake behavior in mouse lines with high (HAB), low (LAB) and normal (NAB) anxiety-related behaviors was monitored for 24 h during baseline and recovery after 6 h sleep deprivation (SD). The amounts of each vigilance state, sleep architecture, and EEG spectral variations were compared between the mouse lines. In comparison to NAB mice, HAB mice slept more and exhibited consistently increased delta power during non-rapid eye movement (NREM) sleep. Their sleep patterns were characterized by heavy fragmentation, reduced maintenance of wakefulness, and frequent intrusions of rapid eye movement (REM) sleep. In contrast, LAB mice showed a robust sleep-wake rhythm with remarkably prolonged sleep latency and a long, persistent period of wakefulness. In addition, the accumulation of delta power after SD was impaired in the LAB line, as compared to HAB mice.

Conclusions/Significance

Sleep-wake patterns were significantly different between HAB and LAB mice, indicating that the genetic predisposition to extremes in trait anxiety leaves a biological scar on sleep quality. The enhanced sleep demand observed in HAB mice, with a strong drive toward REM sleep, may resemble a unique phenotype reflecting not only elevated anxiety but also a depression-like attribute.

A meta-analysis of electroencephalographic sleep in depression: evidence for genetic biomarkers

BACKGROUND

Research on whether any electroencephalographic (EEG) sleep abnormalities observed among individuals with major depressive disorder (MDD) represent genetic biomarkers remains inconclusive. We aimed to identify EEG-based biomarkers of MDD through a review of studies from three populations: individuals with MDD, individuals with MDD under remission, and never depressed high-risk probands (HRPs) of individuals with MDD.

METHODS

We searched databases such as MEDLINE and PsycINFO for EEG studies published since 1970. Of the 886 records, our selection criteria identified 56 studies that employed standardized EEG scoring procedures and addressed confounds such as participant reactivity and drug effects. We then used fixed-effects models to calculate average weighted mean differences in EEG parameters between clinical groups across these studies.

RESULTS

Individuals with MDD differed significantly from control subjects on several EEG variables. However, remitted individuals showed normalization of all affected EEG parameters except rapid eye movement (REM) density and slow-wave sleep (SWS). Surprisingly, proportion of SWS was significantly shorter during remission than depression. Never-depressed HRPs also exhibited significantly elevated REM density and reduced SWS. Finally, these parameters constituted the only two EEG variables that were not moderated by depression severity.

CONCLUSIONS

Individuals experiencing MDD and those in remission exhibit increased REM density and shortened SWS, as do HRPs with no history of MDD. Thus, this combination of EEG features may represent a genetic biomarker of MDD. Further, SWS appears to be shorter during remission than depression, suggesting its role as both a genetic marker as well as a biological scar of the disorder.

Relationships between menopausal and mood symptoms and EEG sleep measures in a multi-ethnic sample of middle-aged women: the SWAN sleep study

STUDY OBJECTIVES

Examine associations of vasomotor and mood symptoms with visually scored and computer-generated measures of EEG sleep.

DESIGN

Cross-sectional analysis.

SETTING

Community-based in-home polysomnography (PSG).

PARTICIPANTS

343 African American, Caucasian, and Chinese women; ages 48-58 years; pre-, peri- or post-menopausal; participating in the Study of Women's Health Across the Nation Sleep Study (SWAN Sleep Study).

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Measures included PSG-assessed sleep duration, continuity, and architecture, delta sleep ratio (DSR) computed from automated counts of delta wave activity, daily diary-assessed vasomotor symptoms (VMS), questionnaires to collect mood (depression, anxiety) symptoms, medication, and lifestyle information, and menopausal status using bleeding criteria. Sleep outcomes were modeled using linear regression. Nocturnal VMS were associated with longer sleep time. Higher anxiety symptom scores were associated with longer sleep latency and lower sleep efficiency, but only in women reporting nocturnal VMS. Contrary to expectations, VMS and mood symptoms were unrelated to either DSR or REM latency.

CONCLUSIONS

Vasomotor symptoms moderated associations of anxiety with EEG sleep measures of sleep latency and sleep efficiency and was associated with longer sleep duration in this multi-ethnic sample of midlife women.

The two-factor structure of sleep complaints and its relation to depression and anxiety

Although sleep complaints are common in depression and anxiety, there is little agreement as to how they should be organized and assessed. It is also unclear whether sleep complaints show specificity with certain disorders or whether they are nonspecific symptoms. The authors examined the structure of sleep complaints and the relations of these complaints to depression and anxiety in 3 samples: college students, older adults, and psychiatric patients. Exploratory and confirmatory factor analyses indicated that sleep complaints consistently defined 2 distinct dimensions: Insomnia and Lassitude. The Insomnia factor included indicators of early, middle, and late insomnia, as well as poor sleep quality. The Lassitude factor included measures of hypersomnia, fatigue, and sleepiness. Both factors were significantly related to symptoms and diagnoses of depression and anxiety. However, Lassitude was more strongly related to symptoms of depression and anxiety than was Insomnia. In addition, Lassitude showed specificity to measures and diagnoses of depression compared with anxiety disorders. This specificity can be explained by Lassitude's relation with negative and positive emotionality, both of which are components of depression.

Nighttime heart rate and survival in depressed patients post acute myocardial infarction

OBJECTIVES

To determine if: 1) depressed patients with a recent acute myocardial infarction (AMI) have higher nighttime heart rate (HR) than nondepressed patients, and 2) elevated nighttime HR is associated with decreased survival post AMI. Depression is a risk factor for mortality post AMI. It is also associated with sleep disturbances and with elevated HR, which may be more pronounced at night. Resting and 24-hour HR have been found to predict mortality in patient and community samples.

METHODS

Ambulatory electrocardiographic data were obtained from 333 depressed patients and 383 nondepressed patients with recent AMI. They were followed for up to 30 months (median = 24 months).

RESULTS

Depressed patients had higher nighttime HR (70.7 +/- 0.7 versus 67.7 +/- 0.6 beats per minute (bpm); p = .001), and daytime HR (76.4 +/- 0.7 versus 74.2 +/- 0.6 bpm; p = .02) than nondepressed patients, even after adjusting for potential confounds. Depression (hazard ratio (Haz R) = 2.19; p = .02) and nighttime HR (Haz R = 1.03; p = .004), but not daytime HR, predicted survival after adjusting for other major predictors and for each other. The interaction between nighttime HR and depression on survival approached, but did not achieve, significance (p = .08).

CONCLUSIONS

Mean day and nighttime HR values are higher in depressed patients than in nondepressed patients post AMI. Depression and elevated nighttime HR, but not daytime HR, are independent predictors of survival in these patients. Although depressed patients have a higher nighttime HR than nondepressed patients, nighttime HR predicts mortality in both depressed and nondepressed patients.

Effects of total sleep deprivation in major depression: overnight improvement of mood is accompanied by increased pain sensitivity and augmented pain complaints

OBJECTIVE

Major depressive disorder (MDD) is associated with more pain complaints and an altered pain perception. Studies regarding the longitudinal relationship between depressive symptoms and pain processing have rarely been performed and have produced inconsistent results. To clarify how short-term alleviation of depressive mood is linked to changes in pain processing, the effect of sleep deprivation (SD) on pain and somatosensory thresholds, pain complaints, and mood was investigated in MDD patients.

METHODS

Nineteen drug-free inpatients with Diagnostic and Statistical Manual of Mental Disorders, fourth edition, diagnosis of MDD were investigated for 3 weeks. All patients received cognitive-behavioral therapy and were randomized to obtain either additional SD therapy (six nights of total SD, separated by recovery sleep) or no SD therapy (control group). Heat/cold pain thresholds, warmth/cold thresholds, measures of current pain complaints, and mood were assessed the evening before and the morning after SD as well as before and after a normal night sleep in the control group. Long-term changes of depressive symptomatology were assessed by weekly mood ratings.

RESULTS

Both treatment groups improved markedly in mood over the 3-week treatment period. SD regularly induced a moderate but statistically nonsignificant overnight improvement of mood, which was abolished by recovery sleep. Compared with the control condition, SD significantly decreased heat pain thresholds and nearly significantly cold pain thresholds; SD significantly augmented pain complaints the next morning. No such effects were observed for somatosensory thresholds.

CONCLUSIONS

SD induced differential short-term effects on mood and pain, with the patients being less depressed but more pain vulnerable.

Financial strain is a significant correlate of sleep continuity disturbances in late-life

Although psychological stress has been associated with disturbed sleep in younger populations, little is known about the stress-sleep relationship in late-life. In the present study, we evaluated relationships among a chronic stressor, ongoing financial strain, and sleep in a heterogenous sample (n=75) of community-dwelling elders (mean age=74.0 years). Self-report measures included ongoing financial strain, mental health, physical health and subjective sleep quality. Sleep duration, continuity, and architecture were measured by polysomnography (PSG). Analysis of variance and regression were used to test the hypothesis that ongoing financial strain is a significant correlate of disturbed sleep in the elderly. Covariates included age, sex, mental health and physical health. Analyses revealed that ongoing financial strain is a significant correlate of PSG-assessed sleep latency, wakefulness after sleep onset, and sleep efficiency. After adjusting for the effects of age, sex, mental health, and physical health on sleep, ongoing financial strain was associated with lower sleep efficiency (p<.01). Our results show that chronic stress, as measured by ongoing financial strain, is a significant correlate of sleep disturbances in the elderly, even after adjusting for factors known to impact sleep in late-life.

Sleep and psychiatry

Psychiatric disorders constitute 15.4% of the disease burden in established market economies. Many psychiatric disorders are associated with sleep disturbances, and the relationship is often bidirectional. This paper reviews the prevalence of various psychiatric disorders, their clinical presentation, and their association with sleep disorders. Among the psychiatric disorders reviewed are affective disorders, psychosis, anxiety disorders (including posttraumatic stress disorder), substance abuse disorders, eating disorders, and attention deficit/hyperactivity disorders. The spectrum of associated sleep disorders includes insomnia, hypersomnia, nocturnal panic, sleep paralysis, hypnagogic hallucinations, restless legs/periodic limb movements of sleep, obstructive sleep apnea, and parasomnias. The effects on sleep of various psychotropic medications utilized to treat the above psychiatric disorders are summarized.

Effects of sertraline on sleep architecture in patients with depression

Previous studies indicate that selective serotonin reuptake inhibitors (SSRIs), including fluoxetine, fluvoxamine, citalopram and paroxetine, suppress rapid eye movement sleep, and increased nocturnal arousals. There has been no published report of the impact of sertraline on the sleep of depressed patients. This study examines such effects. Forty-seven patients with major depressive disorder, randomized to double-blind treatment with sertraline or placebo, completed sleep studies before and after 12 weeks of pharmacotherapy. Groups were compared using multivariate analyses of covariance and/or analyses of covariance to examine 4 empirically defined sets of sleep measures. Compared to the placebo-treated group, patients who received sertraline experienced an increase in delta wave sleep in the first sleep cycle and prolonged rapid eye movement (REM) sleep latency. Although, sertraline therapy decreased the average number of REM periods (from 3.86 to 2.40), the activity of both REM period 1 and REM period 2 was significantly increased. Aside from an increase in sleep latency, sertraline therapy was not associated with a worsening of measures of sleep continuity. There was also no significant difference between the groups on a measure of subjective sleepiness. These findings are both similar and different from those observed in previous studies of other SSRIs. The increase in delta sleep ratio and consolidation of REM sleep may have some other clinical implications. However, the generalizability of these findings is limited because of a number of reasons. Further studies are needed to examine the effects of SSRIs in acute treatment of depressed patients with severe insomnia, and the relationship of acute changes and relapse prevention of recurrent depression.

Correlation of subjective and objective sleep measurements at different stages of the treatment of depression

Studies of the correlation of subjective and objective sleep measures in depressed patients have produced mixed results so far. Further, they were carried out in sleep laboratories and tended to obtain one-off assessments, thus not taking into account the effect of treatment. We investigated forty (40) patients over the course of 8-week treatment of depression with either paroxetine or nefazodone. We used home polysomnography at baseline, nights 3 and 10, and week 8 of treatment, with extensive assessments of subjective sleep, the morning after each sleep recording. The patients were able to judge accurately their total sleep time and sleep onset latency, both before and during treatment. However, they were inaccurate in estimating the number of times they woke up during the night. Sleep satisfaction correlated negatively with Stage 1 sleep at baseline. Sleep quality was represented by a combination of subjective parameters measuring the ease of initiation and maintenance of sleep, and it appeared to derive from slow wave sleep and sleep continuity as seen in polysomnography. The partial discrepancy between subjective and objective measures suggests that a cognitive element is combined with the biological element to produce the sleep problems reported by depressed patients.

Sleep and treatment response in depression: new findings using power spectral analysis

This study examined quantitative measures of sleep electroencephalogram (EEG) and phasic rapid eye movements (REM) as correlates of remission and recovery in depressed patients. To address correlates of remission, pre-treatment EEG sleep studies were examined in 130 women outpatients with major depressive disorder treated with interpersonal psychotherapy (IPT). To address correlates of recovery, baseline and post-treatment EEG sleep studies were examined in 23 women who recovered with IPT alone and 23 women who recovered with IPT+fluoxetine. Outcomes included EEG power spectra during non-rapid eye movement (NREM) sleep and REM sleep and quantitative REMs. IPT non-remitters had increased phasic REM compared with remitters, but no significant differences in EEG power spectra. IPT+fluoxetine recoverers, but not IPT recoverers, showed increases in phasic REM and REM percentage from baseline to recovery. In NREM sleep, the IPT+fluoxetine group showed a decrease in alpha power from baseline to recovery, while the IPT group showed a slight increase. The number of REMs was a more robust correlate of remission and recovery than modeled quantitative EEG spectra during NREM or REM sleep. Quantitative REMs may provide a more direct measure of brainstem function and dysfunction during REM sleep than quantitative sleep EEG measures.

Sleep in depression and sleep deprivation: a brief conceptual review

Risk factors for somnipathies are psychological stress or psychiatric illness. More severe sleep difficulties have been found to be clearly related to psychiatric illness such as depression and phobias, as well as to addiction. Somnipathies can objectively be identified by means of polygraphy. Overall, polysomnographic measures in patients with affective disorders differ most frequently and significantly from those in normal control subjects. Persistent sleep disturbances are associated with significant risk of both relapse and recurrence in mood disorders and an increased risk of suicide. In addition to changes in sleep architecture, patients with major depression show profoundly altered patterns of nocturnal hormone secretion, possibly through mechanisms that link regulation of sleep with neuroendocrine activity. Basic and clinical approaches of sleep research established neurobiological models into the underlying pathophysiology associated with psychiatric disorders.

Pretreatment REM sleep and subjective sleep quality distinguish depressed psychotherapy remitters and nonremitters

BACKGROUND

We compared pretreatment subjective and electroencephalographic sleep measures among depressed patients who remitted with psychotherapy alone and those who did not remit.

METHODS

Patients were 111 midlife women with recurrent major depressive disorder. Baseline psychiatric ratings and sleep studies were conducted prior to treatment with weekly interpersonal psychotherapy. Remission was defined as a score of < or = 7 for 3 consecutive weeks on the Hamilton Depression Rating Scale. Clinical and sleep measures were compared between remitters (n = 62) and nonremitters (n = 49) using t tests and random regression. Linear discriminant function analyses were used to categorize remitters and nonremitters on the basis of sleep measures.

RESULTS

Treatment nonremitters had significantly worse subjective sleep quality and significantly elevated phasic REM sleep as measured by multivariate and univariate analyses. The linear accumulation of REM activity during sleep occurred at a significantly higher rate in nonremitters than in remitters. Linear discriminant function analyses based on subjective sleep quality and REM activity correctly identified 68.3% of nonremitters and 68.5% of remitters.

CONCLUSIONS

These findings highlight the role of subjective and REM sleep measures as correlates of short-term psychotherapy treatment response in major depressive disorder. Disturbed sleep may be a physiological indicator of increased limbic and brain stem arousal.