Psychological Medicine



Original Article

Disrupting life events and the sleep-wake cycle in depression


PATRICIA L. HAYNES a1c1, JOHN R. McQUAID a2, SONIA ANCOLI-ISRAEL a2 and JENNIFER L. MARTIN a3
a1 University of Arizona, Department of Psychiatry, Tucson, AZ, USA
a2 University of California, San Diego, and Veterans Affairs San Diego Healthcare System, San Diego, CA, USA
a3 University of California, Los Angeles and Greater Los Angeles Veterans Affairs Healthcare System, Sepulveda, CA, USA

Article author query
haynes pl   [PubMed][Google Scholar] 
mcquaid jr   [PubMed][Google Scholar] 
ancoli-israel s   [PubMed][Google Scholar] 
martin jl   [PubMed][Google Scholar] 

Abstract

Background. Social rhythm disruption life events are significant predictors of mood relapse in bipolar patients. However, no research has examined the relationship between these events and their hypothesized mechanism of action: disrupted sleep-wake patterns. The goal of this study was to test whether participants with major depressive disorder have a greater disruption of daily sleep and motor activity following disrupting life events when compared to normal controls.

Method. Over the course of 2 weeks, 39 normal controls and 39 individuals with major depressive disorder completed life events interviews and wore actigraphs to obtain estimates of sleep/wake activity.

Results. Statistically significant interactions indicated that the presence of at least one disrupting life event in the previous 4 months correlated with elevations in the amount of time spent awake after sleep onset [β=0·45, ΔF(1,73)=4·80, p<0·05], and decreases in the percentage of time spent asleep [β=−0·53, ΔF(1,73)=6·57, p<0·05], in depressed individuals but not in normal controls.

Conclusions. The results indicated that depressed individuals may be more susceptible to the effects of life events on sleep than normal controls. This is the first study to date to correlate life events with objective measures of sleep. However, prospective longitudinal research is necessary to clarify the temporal relationship among these variables.

(Published Online July 12 2006)


Correspondence:
c1 Department of Psychiatry, University of Arizona, 1501 N. Campbell Avenue, P.O. Box 245002, Tucson, AZ 85724-5002, USA. (Email: thaynes@email.arizona.edu)


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