Circadian preference in bipolar disorder.
OBJECTIVE
A role for circadian rhythm abnormalities in the pathogenesis of bipolar disorder (BD) has been suggested. The present study assessed circadian preference, a subjective preference for activities in the morning or evening related to chronotype.


METHODS
The sample was comprised of 81 outpatients with BD in remission and 79 control subjects. Circadian preference was derived from an interview evaluating biological rhythms and sleep pattern from the Pittsburgh Sleep Quality Index.


RESULTS
Patients were significantly more likely to have an evening preference than control subjects. Circadian preference was also associated with sleep latency.


CONCLUSIONS
The association of evening preference and longer sleep latency may be related to the frequent clinical observation of a sleep/wake cycle reversal in bipolar disorder.
Molecular Psychiatry Laboratory and INCT Translational Medicine, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
Larriany Maria Falsin
LM
Giglio
Pedro V S
PV
Magalhães
Mônica Levy
ML
Andersen
Julio Cesar
JC
Walz
Lourenço
L
Jakobson
Flávio
F
Kapczinski
D000328:Adult; D001714:Bipolar Disorder / Q000453:epidemiology / Q000523:psychology*; D001938:Brazil; D002755:Choice Behavior; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020178:Sleep Disorders, Circadian Rhythm / Q000453:epidemiology / Q000523:psychology; D013223:Statistics as Topic; D014851:Wakefulness