Bipolar Disorder and Substance Abuse

Abstract

Objectives: To review evidence about mechanisms and consequences of relationships between bipolar and substance use disorders.

Methods: Articles were identified using a MEDLINE search linking (1) bipolar disorder to substance use disorders, alcoholism, and specific drugs, (2) bipolar disorder and substance abuse to treatment strategies, and (3) bipolar disorder or substance abuse to behavioral sensitization, impulsivity, and suicide. We attempted to select only the most relevant refereed articles. In addition to articles found in the search, key references cited in the articles were used.

Results: Substance use disorders and bipolar disorders are associated with mutually increased risk. Patients with the combination are more impulsive and are at greater risk for suicidal or violent behavior than are subjects with either illness alone. Compared to subjects with bipolar disorder who do not have a substance use disorder, those with combined disorders have earlier onset of illness, more frequent hospitalizations, and are more likely to experience mixed episodes. Both disorders must be addressed specifically for treatment to be effective. Treatment options are expanding, but few have been adequately studied.

Conclusions: The nature of the apparent link between bipolar disorder and substance use disorders suggests that they share common mechanisms. Candidate mechanisms include abnormal regulation of the initiation of behavior leading to abnormal reward sensitivity and increased impulsivity, and increased susceptibility to behavioral sen-sitization.

Key Words:

• Bipolar disorder
• substance use disorders
• alcoholism
• stimulants
• behavioral sensitization
• impulsivity