Mood Disorders Predict Later Substance Abuse Problems
Mania symptoms and bipolar disorder II more likely to lead to substance abuse than depression
• Science Update
People with manic symptoms and bipolar disorder type II are at significant risk of later developing an alcohol abuse or dependence problem, a long-term study conducted in Switzerland confirms. The study was published in the January 2008 issue of the Archives of General Psychiatry.
Extensive research using retrospective reports has demonstrated a clear association between mood disorders and substance abuse. But few prospective long-term studies have been able to show evidence of this.
Kathleen Merikangas, Ph.D., of the NIMH Mood and Anxiety Disorders Program, collaborated with colleagues to follow 591 people (292 men and 299 women) over two decades, beginning in 1978 when the participants were 19 or 20 years old. The participants were interviewed six times between 1979 and 1999.
By 1993, almost 10 percent met criteria for major depression. Although bipolar disorder type I was very rare, 4 percent met criteria for bipolar disorder II—a milder form of the disorder. In addition, 24 percent had symptoms of mania but did not meet specific criteria for bipolar disorder.
By 1999, when participants were about 40 years old, 18 percent met criteria for alcohol abuse or dependence problems, while 8 percent met criteria for cannabis (marijuana) abuse and 3 percent met criteria for benzodiazepine abuse.
Merikangas and colleagues found that people who showed symptoms of mania, but who did not meet criteria for bipolar disorder, were at significantly greater risk for later developing an alcohol abuse or dependence problem. Those with bipolar disorder II were even more at risk of developing an alcohol problem or benzodiazepine abuse problem. Major depression was associated only with developing a benzodiazepine abuse problem among this population.
“The findings confirm the link between mood disorders and substance abuse or dependence problems,” said Dr. Merikangas. “They also suggest that earlier detection of bipolar symptoms could help to prevent consequent substance abuse problems.”
The study was known as the Zurich Cohort Study.
Merikangas, KR, Herrell R, Swendsen J, Rossler W, Ajdacic-Gross V, Angst J. Specificity of bipolar spectrum conditions in the comorbidity of mood and substance abuse disorders . Archives of General Psychiatry. 2008;65(1): 47-52.