The natural history of insomnia: acute insomnia and first-onset depression.
OBJECTIVE
While many studies have examined the association between insomnia and depression, no studies have evaluated these associations (1) within a narrow time frame, (2) with specific reference to acute and chronic insomnia, and (3) using polysomnography. In the present study, the association between insomnia and first-onset depression was evaluated taking into account these considerations.


METHODS
A mixed-model inception design.


METHODS
Academic research laboratory.


METHODS
Fifty-four individuals (acute insomnia [n = 33], normal sleepers [n = 21]) with no reported history of a sleep disorder, chronic medical condition, or psychiatric illness.


METHODS
N/A.


RESULTS
Participants were assessed at baseline (2 nights of polysomnography and psychometric measures of stress and mood) and insomnia and depression status were reassessed at 3 months. Individuals with acute insomnia exhibited more stress, poorer mood, worse subjective sleep continuity, increased N2 sleep, and decreased N3 sleep. Individuals who transitioned to chronic insomnia exhibited (at baseline) shorter REM latencies and reduced N3 sleep. Individuals who exhibited this pattern in the transition from acute to chronic insomnia were also more likely to develop first-onset depression (9.26%) as compared to those who remitted from insomnia (1.85%) or were normal sleepers (1.85%).


CONCLUSIONS
The transition from acute to chronic insomnia is presaged by baseline differences in sleep architecture that have, in the past, been ascribed to Major Depression, either as heritable traits or as acquired traits from prior episodes of depression. The present findings suggest that the "sleep architecture stigmata" of depression may actually develop over the course transitioning from acute to chronic insomnia.
Northumbria Centre for Sleep Research, Northumbria University, Newcastle, UK.
Jason G
JG
Ellis
Department of Psychiatry, University of Pennsylvania, PA.
Michael L
ML
Perlis
Department of Psychology, Université Laval, Quebec, Canada.
Célyne H
CH
Bastien
Institute of Mental Health and Wellbeing, University of Glasgow, UK.
Maria
M
Gardani
Nuffield Department of Clinical Neurosciences/Sleep & Circadian Neuroscience Institute, University of Oxford, UK.
Colin A
CA
Espie
D000208:Acute Disease; D000328:Adult; D000339:Affect; D017668:Age of Onset; D016022:Case-Control Studies; D002908:Chronic Disease; D003863:Depression / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D018450:Disease Progression; D004198:Disease Susceptibility; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D011594:Psychometrics; D012307:Risk Factors; D012890:Sleep; D007319:Sleep Initiation and Maintenance Disorders / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology*; D013315:Stress, Psychological / Q000150:complications; D013997:Time Factors; D055815:Young Adult
Acute insomnia; chronic insomnia; first-onset depression; natural history; precipitating factors; short-term insomnia