Reasons for substance use in dual diagnosis bipolar disorder and substance use disorders: a qualitative study.

Background: Few systematic studies have examined the reasons why patients with bipolar disorder and substance use disorders misuse alcohol and drugs of abuse. Such reasons may depend heavily on context so qualitative research methods that made no prior theoretical assumptions were employed. We explored the reasons patients give for misusing drugs and alcohol and how these relate to their illness course.

Method: Qualitative semi-structured interviews and thematic analysis with a purposive sample of 15 patients with bipolar disorder and a current or past history of drug or alcohol use disorders.

Results: Patients based their patterns of and reasons for substance use on previous personal experiences rather than other sources of information. Reasons for substance use were idiosyncratic, and were both mood related and unrelated. Contextual factors such as mood, drug and social often modified the patient's personal experience of substance use. Five thematic categories emerged: experimenting in the early illness; living with serious mental illness; enjoying the effects of substances; feeling normal; and managing stress.

Limitations: The prevalence of these underlying themes was not established and the results may not apply to populations with different cultural norms.

Conclusions: Patterns of substance use and reasons for use are idiosyncratic to the individual and evolve through personal experience. Motivating the patient to change their substance use requires an understanding of their previous personal experience of substance use both in relation to the different phases of their bipolar disorder and their wider personal needs.