The co-occurrence of bipolar and substance use disorders

Substance use disorders are exceptionally common in bipolar patients. Altho ugh the frequency of this co-occurrence is well-documented, the reasons for this association are not clear In this review the authors examine four pot ential hypotheses for why substance use and bi- Polar disorders co-occur: ( a) substance abuse occurs as a symptom of bipolar disorder; (b) substance a buse is an attempt by bipolar patients to self-medicate symptoms; (c) subst ance abuse causes bipolar disorder; and (d) substance use and bipolar disor ders share a common risk factor. None of these four hypotheses have unequiv ocal support for explaining all cases of bipolar and substance use disorder co-occurrence, and it is probable that all four mechanisms play some role in the excess of substance abuse observed in bipolar patients. Additional s tudies are warranted to clarify the complex relationships between these two conditions as better understanding of this co-occurrence could lead to bet ter treatment for Patients afflicted with both disorders. (C) 2000 Elsevier Science Ltd.