Study details risk factors for substance use disorders after manic episode

(Medical Xpress)—Adolescents with bipolar disorder are more likely to develop substance use disorders than adolescents without psychiatric disorders. Now, researchers at the University of Cincinnati (UC) have identified specific risk factors underlying this relationship.

The researchers, led by Melissa DelBello, MD, the Dr. Stanley and Mickey Kaplan Chair of Psychiatry and Behavioral Neuroscience, publish their findings in the July issue of the Journal of Child & Adolescent Psychiatry. DelBello is the senior author.

The researchers studied 103 adolescents between 12 and 20 years old who were diagnosed with bipolar I disorder and hospitalized for the first time for a manic episode. Of those 103 adolescents, 32 were already diagnosed with a substance use disorder at the time of hospitalization.

Of the 71 participants who did not have a substance use disorder at hospitalization, 17 (24 percent) developed a substance use disorder during follow-up, ranging from 17 weeks to 283 weeks. The most common substance use disorders were alcohol abuse or dependence, (13 of the 17 participants), followed by cannabis abuse or dependence (12 participants). (Some participants developed substance use disorders involving both cannabis and alcohol.)

Participants who developed a substance use disorder had significantly later age of onset of bipolar disorder than those who did not (14.4 years vs. 12.1 years). Psychosis at baseline was significantly associated with developing a substance abuse disorder. In addition, comorbid disruptive behavior disorders and post-traumatic stress disorders (PTSD) were significantly associated with developing a substance use disorder during follow-up.

Conversely, treatment with stimulants before the onset of bipolar disorder was significantly associated with not developing a substance use disorder during follow-up.

"Our analyses revealed several risk factors that were associated with developing a new substance use disorder after the first manic episode in adolescence," says DelBello. "Psychosis and PTSD showed the strongest evidence of predicting a new-onset substance use disorder."

DelBello notes that self-medication could be a prominent reason for developing a substance use disorder after the onset of bipolar disorder. Additionally, the impulsivity associated with mania might contribute to developing a substance use disorder.

DelBello also noted that participants who had been prescribed stimulants before the index episodes had roughly one-fourth the risk for developing a substance use disorders.

"One explanation for this is that the stimulants were effectively treating ADHD, which has been shown to minimize risk for developing a substance use disorder," she says.

DelBello says the study offers several clinical insights, including:

• Adolescents with bipolar disorder have a particularly high risk of developing a substance use disorder.
• Substance use should be closely monitored in adolescents with bipolar disorder, and clinicians should advise adolescents with bipolar disorder and their parents about the risk of developing substance use disorders and the associated poor outcomes.
• In particular, close attention should be given to adolescents with bipolar disorder who have experienced trauma (mental or physical) and/or who have psychotic symptoms.