Despite the prevalence of sleep complaints among psychiatric patients, few questionnaires have been specifically designed to measure sleep quality in clinical populations. The Pittsburgh Sleep Quality Index (PSQI) is a self-rated questionnaire which assesses sleep quality and disturbances over a 1-month time interval. Nineteen individual items generate seven "component" scores: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction. The sum of scores for these seven components yields one global score. Clinical and clinimetric properties of the PSQI were assessed over an 18-month period with "good" sleepers (healthy subjects, n = 52) and "poor" sleepers (depressed patients, n = 54; sleep-disorder patients, n = 62). Acceptable measures of internal homogeneity, consistency (test-retest reliability), and validity were obtained. A global PSQI score greater than 5 yielded a diagnostic sensitivity of 89.6% and specificity of 86.5% (kappa = 0.75, p less than 0.001) in distinguishing good and poor sleepers. The clinimetric and clinical properties of the PSQI suggest its utility both in psychiatric clinical practice and research activities.

The Pittsburgh Sleep Quality Index: A new instrument for psychiatric practice and research.

Genetic and metabolic studies have been done on a large kindred in which several males are affected by a syndrome of borderline mental retardation and abnormal behavior. The types of behavior that occurred include impulsive aggression, arson, attempted rape, and exhibitionism. Analysis of 24-hour urine samples indicated markedly disturbed monoamine metabolism. This syndrome was associated with a complete and selective deficiency of enzymatic activity of monoamine oxidase A (MAOA). In each of five affected males, a point mutation was identified in the eighth exon of the MAOA structural gene, which changes a glutamine to a termination codon. Thus, isolated complete MAOA deficiency in this family is associated with a recognizable behavioral phenotype that includes disturbed regulation of impulsive aggression.

https://science.sciencemag.org/content/sci/262/5133/578.full.pdf

Abnormal behavior associated with a point mutation in the structural gene for monoamine oxidase A

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

A cognitive model of insomnia.

The hyperarousal model of insomnia: A review of the concept and its evidence

Ten insomniacs and matched control subjects, in whom major physiologic disorders such as sleep apnea and nocturnal myoclonus were ruled out, underwent studies of sleep, temperature, motor activity, cognitive performance, and perception of depth of sleep. Subjective descriptions of sleep differed significantly between insomniacs and normals on a variety of variables. In contrast, polysomnographic evaluation showed increased intermittent waking time and decreased sleep efficiency, and only a tendency toward decreased total sleep and increased sleep latency. Minnesota Multiphasic Personality Inventory (MMPI) evaluation revealed that insomniacs had higher scores on the F,D, and SI scales, and lower values on the K scale. On cognitive testing, insomniacs did well on tests of episodic (recent) memory, but displayed major deficits in accessing semantic memory (retrieval of material already known). Compared to normals, insomniacs described rapid eye movement (REM) sleep as relatively “light” sleep.

The experience of insomnia and daytime and nightime functioning

Eight patients with major depressive disorder (seven bipolar and one unipolar) and matched controls had sleep studies, on which frequency analysis of the electroencephalogram (EEG) was performed. Total sleep and sleep efficiency were decreased in the patients, but there was no significant difference in rapid eye movement (REM) latency between the two groups. Frequency analysis revealed no group differences in power in the delta band (0.23-2.5 Hz) or the whole EEG spectrum (0.23-25 Hz). These findings suggest that mean REM latencies are not always shorter in major depression. The results are discussed in light of a previous report of decreased delta energy in the sleep EEG of unipolar patients.

Frequency analysis of the sleep EEG in depression.

\s=b\ Eighty-one percent of 339 alcoholics participating in a research program were found to have associated mental disorders. Alcoholics with onset of heavy drinking before 20 years of age had significantly more antisocial personality traits, drug abuse, bipolar disorder, panic disorder, suicide attempts, and paternal alcoholism than alcoholics with onset after age 20 years. Alcoholics with onset before and after 20 years of age also differed significantly from each other for cerebrospinal fluid concentrations of diazepam-binding inhibitor and somatostatin. These results support the notion that age of onset may delineate subgroups of alcoholics with significant clinical and neurochemical differences. (Arch Gen Psychiatry. 1991 ;48:423-427)

Relationship to Age of Onset and Cerebrospinal Fluid Neuropeptides

Ten insomniacs with age- and sex-matched controls had studies of baseline sleep, relation of polygraphically defined sleep to retrospective reports, and arousal thresholds to electronic tones or to a recording of a voice calling out the subject's name. The two groups differed in 10 out of 13 questions about habitual sleep and daytime feelings. In contrast, polygraphic measures of baseline sleep indicated only that insomniacs tended to have slightly less total sleep and had a small but significant increase in early morning awakening time. Unlike the descriptions of habitual sleep, the subjects' retrospective reports of the previous night's sleep differed significantly only for the variable of total sleep time, and there were virtually no differences in the description of their status at a given moment. Auditory arousal thresholds were similar in the two groups, and both went back to sleep and stayed asleep with equal facility. These findings suggest that subjectively poor sleep is not necessarily "light" sleep. For both groups, arousal thresholds differed across the sleep stages, and thresholds to hearing the subject's name were lower than those in response to electronic tones. Although insomniacs had as much polygraphically defined sleep as controls between the forced awakenings of the arousal threshold studies, they perceived their sleep to be only approximately half as long. Insomniacs described themselves as having been awake more frequently than controls in 8 out of 10 forced awakening situations. In one case, insomniacs also overestimated the time between awakenings. In both groups, there was little relationship between reported habitual aspects of sleep and baseline polygraphically defined sleep variables. On questionnaires the following mornings, however, in both groups there was a positive correlation of subjective quality of sleep on the baseline nights with percentage of rapid eye movement sleep, and a negative correlation to various aspects of slow-wave sleep.

A psychophysiological study of insomnia.

The effects of 4 weeks of treatment with the selective monoamine oxidase (MAO) inhibiting antidepressants clorgyline and pargyline on the sleep of affectively disordered patients were studied. Both inhibitors resulted in near total suppression of REM sleep, a decrease in total sleep time, and an increase in the percent of stage 2 sleep. Clorgyline also increased awake time and decreased total recording period and sleep latency. In general, changes were greater for clorgyline than for pargyline and were about 50% slower to return to baseline after clorgyline compared to pargyline discontinuation. The results were consistent with the hypothesis that selective inhibition of the MAO type A, as produced by clorgyline, is sufficient to induce marked sleep changes. MAO inhibitor-induced receptor changes are proposed to account for the time course of the REM suppression and the REM rebound observed upon withdrawal.

Debra Garnett

Papers

The experience of insomnia and daytime and nightime functioning

Frequency analysis of the sleep EEG in depression.

Relationship to Age of Onset and Cerebrospinal Fluid Neuropeptides

A psychophysiological study of insomnia.

REM sleep suppression induced by selective monoamine oxidase inhibitors.