We reviewed the literature on sleep in psychiatric disorders and evaluated the data by meta-analysis, a statistical method designed to combine data from different studies. A total of 177 studies with data from 7151 patients and controls were reviewed. Most psychiatric groups showed significantly reduced sleep efficiency and total sleep time, accounted for by decrements in non-rapid eye movement sleep. Rapid eye movement sleep time was relatively preserved in all groups, and percentage of rapid eye movement sleep was increased in affective disorders. Reduction in rapid eye movement sleep latency was seen in affective disorders but occurred in other categories as well. Although no single sleep variable appeared to have absolute specificity for any particular psychiatric disorder, patterns of sleep disturbances associated with categories of psychiatric illnesses were observed. Overall, findings for patients with affective disorders differed most frequently and significantly from those for normal controls.

Sleep and Psychiatric Disorders: A Meta-analysis

• Data from all-night EEG sleep studies were used to distinguish normal subjects, primary depressed patients, and primary insomniac patients. In part 1, we compared 41 normal subjects, 56 depressed patients, and 18 insomniacs. In a univariate comparison with normal subjects, depressed patients showed less total sleep, longer sleep latency, more early morning awake time, more intermittent awake time, less delta sleep, less sleep efficiency, and shorter rapid eye movement (REM) latencies; compared with insomniacs, depressed patients showed greater early morning awake time, shorter REM latency, greater REM index, and greater REM density. Using multivariate discriminant analysis, 82% of the sample were correctly classified by diagnosis: 100% of the normal subjects, 72% of the depressed patients, and 77% of the insomniacs. Eight variables contributed to the multivariate separation of depressed individuals from insomniacs and normals: total sleep time, total recording period, sleep efficiency, sleep latency, early morning awake time, awake time, REM time, and REM %. When the discriminant functions were applied to a second group of 18 primary depressed patients, 82% were correctly classified as depressed. These results suggest that primary depressed patients and primary insomniac patients may show relatively characteristic patterns of sleep abnormality.

Successful separation of depressed, normal, and insomniac subjects by EEG sleep data.

https://www.neurologic.theclinics.com/article/S0733-8619(12)00059-X/pdf

Psychiatric disorders and sleep

Recent evidence shows that the temporal alignment between the sleep-wake cycle and the circadian pacemaker affects self-assessment of mood in healthy subjects. Despite the differences in affective state between healthy subjects and patients with psychiatric disorders, these results have implications for analyzing diurnal variation of mood in unipolar and bipolar affective disorders and sleep disturbances in other major psychiatric conditions such as chronic schizophrenia. In a good proportion of patients with depression, mood often improves over the course of the day; an extension of waking often has an antidepressant effect. Sleep deprivation has been described as a treatment for depression for more than 30 years, and approximately 50% to 60% of patients with depression respond to this approach, especially those patients who report that their mood improves over the course of the day. The mechanisms by which sleep deprivation exerts its antidepressant effects are still controversial, but a reduction in rapid eye movement sleep (REM sleep), sleep pressure and slow-wave sleep (SWS), or a circadian phase disturbance, have been proposed. Although several studies support each of these hypotheses, none is sufficient to explain all observations reported to date. Unfortunately, the disturbed sleep-wake cycle or behavioural activities of depressed patients often explain several of the abnormalities reported in the diurnal rhythms of these patients. Thus, protocols that specifically manipulate the sleep-wake cycle to unmask the expression of the endogenous circadian pacemaker are greatly needed. In chronic schizophrenia, significant disturbances in sleep continuity, REM sleep, and SWS have been consistently reported. These disturbances are different from those observed in depression, especially with regard to REM sleep. Circadian phase abnormalities in schizophrenic patients have also been reported. Future research is expected to clarify the nature of these abnormalities.

/pdf/influence-of-sleep-wake-and-circadian-rhythm-disturbances-in-40mr4ud08i.pdf

Influence of sleep-wake and circadian rhythm disturbances in psychiatric disorders.

Sleep in schizophrenia patients and the effects of antipsychotic drugs

An automatic procedure providing information about human systolic blood pressure at each successive heartbeat under routine laboratory conditions is described. Twenty normal male subjects were given feedback of their own systolic pressure, half operantly reinforced for increasing and half reinforced for decreasing their pressure. Significant differences in pressure were obtained in a single session. The apparatus and results suggest a possible approach to the treatment of essential hypertension.

http://science.sciencemag.org/content/sci/163/3867/588.full.pdf

Effects of Feedback and Reinforcement on the Control of Human Systolic Blood Pressure

THE relationship between sleep and schizophrenia, and particularly the dream state and schizophrenia, has long held the neuropsychiatrist's attention and interest. Kraepelin, 1 Jackson, 2 and Jung 3 hypothesized around the turn of the century, that a similarity did indeed exist between the dream state and dementia praecox. Objective methods for studying sleep and dreaming, however, were lacking, and research in the borderland of sleep-schizophrenia remained in the realm of speculation. With the discovery by Aserinsky, Kleitman, and Dement 4-6 in the early 1950's that through all-night electroencephalogram (EEG) recordings, sleep could be qualitatively separated into two distinct interdigitating phases—rapid eye movement (REM) sleep and slow wave sleep, the former being associated with a high percentage of dream recall—the sleepschizophrenia paradigm became subject for the first time to experimental scrutiny. Most sleep studies with schizophrenics since then have focused on the REM state, comparing schizophrenics with their normal counterparts. The

All-night sleep studies of acute schizophrenics.

&NA; Spontaneous skin potential fluctuations (SPF) were recorded during the sleep of 8 acute schizophrenic patients and 6 normal volunteers. While in normals the SPFs decreased during rapid eye movement (REM) sleep and were most numerous during Stages III and IV, the acute schizophrenics had the greatest number of SPFs during REM sleep and waking, and fewest during Stages III and IV sleep. It is hypothesized that this effect represents a lack of normal control during REM sleep in the acute schizophrenic patients. It may be related to the recently reported failure of acute schizophrenics to have post‐REM‐deprivation supranormal levels of REM seen in normals. It is also possibly connected to a hypothesized serotonergic REM system.

Melvin Stern

Papers

Effects of Feedback and Reinforcement on the Control of Human Systolic Blood Pressure

All-night sleep studies of acute schizophrenics.

Abnormalities in skin potential fluctuations during the sleep of acute schizophrenic patients.