Studies have consistently indicated a strong association between mood and substance-related disorders, which is even greater for bipolarity. The goal of this study is to verify the validity of this association throughout the bipolar spectrum and if there is a dose-response gradient.

We performed a systematic review in Medline and Lilacs for articles published since 1980, using the keywords “substance” and “bipolar” associated with “dual diagnosis”, “co occurrence”, “comorbidity” or “coexistence”. 370 articles were retrieved, of which 8 were selected according to the following inclusion criteria: population studies; approaching specifically this comorbidity; and discriminating different subtypes of affective disorders according to DSM (-III, -III-R or IV) or ICD 10 criteria.

56.1 to 62.3% of bipolar patients present any addiction lifetime, which corresponds to an OR of 3.6-18.9. The magnitude of this association is greater for BD I in relation to BD II (OR 3.9-18.9 vs. 3.6-9.0). This co-occurrence is significant even for subsyndromic bipolarity (OR 2.5-4.3). More severe bipolarity coexists with more harmful patterns of substance consumption: BP I is more associated with drug dependence (OR 11.1), while BP II presents a greater chance of substance abuse (OR 3.9). Subsyndromic bipolarity is more associated with alcohol dependence (OR 3.2-23.8).

The whole bipolar spectrum poses a significant chance of a comorbid substance disorder in a dose-response gradient: The greater the severity of bipolar disorder, the greater its association with any addiction and with more harmful patterns of substance consumption.