Do patients with bipolar disorder drink alcohol for different reasons when depressed, manic or euthymic?

OBJECTIVE: Many studies report high prevalence rates for co-morbid alcohol problems in bipolar disorder (BP). Some hypothesize that individuals use alcohol to self-medicate, but few studies examine the range of possible reasons and none explicitly explores the role of mood state. We examined drinking motives in BP depression, (hypo)mania and euthymia according to Cooper's cognitive motivational model of alcohol use (Cooper, 1994).
METHODS: Twenty-seven participants with BP were interviewed using the Drinking Motives Questionnaire. A calendar-based measure of alcohol use--the FORM90--was used to aid recall of drink-related behaviours and estimate alcohol intake. Each participant reported drinking motives and alcohol consumption for 30 consecutive days of euthymia, plus one past depressive and one past (hypo)manic episode.
RESULTS: Estimated alcohol intake was higher when depressed or (hypo)manic compared with euthymia. Drinking motives varied between mood states. Negative internal coping motives were specifically related to depression, whilst positive internal and external motives were more specifically related to (hypo)mania. During euthymia, the patients' motives did not differ from norms.
CONCLUSIONS: This is the first clinical study utilising a clearly defined cognitive motivational model demonstrating that the reasons to drink alcohol in patients with BP are mood-dependent. Interventions aimed at modifying problematic drinking behaviours in this population must take into account both individual and mood state variations in reasons for alcohol consumption. Self-medication or inadequate coping is not sufficient to generally explain alcohol intake across mood states and individuals.