Prevalence and association of comorbid substance dependence on the course and outcome of bipolar disorder: Findings from the bipolar disorder course and outcome study from India (BiD-CoIN study)

Aim: To evaluate the prevalence of substance use disorder (SUD) and its association with the course and outcome of bipolar disorder (BD). Materials and Methods: A total of 773 patients with BD were recruited from 14 centers in different parts of India, and they were evaluated for the prevalence of comorbid substance dependence, course and outcome, subjective cognitive functioning, and disability. Results: About one-fourth (22.9%) of the participants had one or more substance dependence. In terms of specific substance of abuse, 136 (17.6%) had nicotine dependence, 80 (10.3%) patients had alcohol dependence, 13 (1.7%) had cannabis dependence, and nine (1.2%) had opioid dependence. Compared to those without comorbid substance dependence, those with a dual diagnosis (i.e., using at least one substance in a dependent pattern) were less educated, more often males, more often currently single, more often employed, had a lower number of depressive episodes per year of illness, had a higher number of manic and mixed episodes per year of illness in the first 5 years of illness, had a higher level of disability, and more often had a history of hospitalization and a history of receiving electroconvulsive therapy (ECT); also, a higher proportion of them had manic predominant polarity, more often had recurrent mania course, and were more often receiving a combination of lithium and valproate. Conclusion: About one-fourth of BD patients have comorbid SUDs, and presence of SUD has a negative impact on the course and outcome of BD.