A study from the Massachusetts General Hospital (MGH) supports previous reports that adolescents with bipolar disorder are at increased risk for smoking and substance abuse. The article appearing in the June Drug and Alcohol Dependence - describing the largest such investigation to date and the first to include a control group - also indicates that bipolar-associated risk is independent of the risk conferred by other disorders affecting study participants.
"This work confirms that bipolar disorder (BPD) in adolescents is a huge risk factor for smoking and substance abuse, as big a risk factor as is juvenile delinquency," says Timothy Wilens, MD, director of Substance Abuse Services in MGH Pediatric Psychopharmacology, who led the study. "It indicates both that young people with BPD need to carefully be screened for smoking and for substance use and abuse and that adolescents known to abuse drugs and alcohol - especially those who binge use - should also be assessed for BPD."
It has been estimated that up to 20 percent of children and adolescents treated for psychiatric problems have bipolar disorder, and there is evidence that pediatric and adolescent BPD may have features, such as particularly frequent and dramatic mood swings, not found in the adult form of the disorder. While elevated levels of smoking and substance abuse previously have been reported in young and adult BPD patients, it has not been clear how the use and abuse of substances relates to the presence of BPD or whether any increased risk could be attributed to co-existing conditions such as attention-deficit hyperactivity disorder (ADHD), conduct disorder or anxiety disorders.
The current study analyzes extensive data - including family histories, information from primary care physicians, and a detailed psychiatric interview - gathered at the outset of a continuing investigation following a group of young BPD patients into adulthood. In addition to 105 participants with diagnosed BPD, who enrolled at an average age of 14, the study includes 98 control participants of the same age, carefully screened to rule out mood disorders.
Incidence of each measure - alcohol abuse or dependence, drug abuse or dependence, and smoking - was significantly higher in participants with BPD than in the control group. Overall, rates of substance use/abuse were 34 percent in the bipolar group and 4 percent in controls. When adjusted to account for co-occurring behavioral and psychiatric conditions, the results still indicated significantly higher risk in the bipolar group. Analyzing how the onset of bipolar symptoms related to when substance abuse began, revealed that BPD came first in most study participants.
The data also indicated that bipolar youth whose symptoms began in adolescence were more likely to abuse drugs and alcohol than were those whose symptoms began in childhood. "It could be that the onset of mood dysregulation in adolescence puts kids at even higher risk for poor judgement and self-medication of their symptoms," Wilens says. "It also could be that some genetic switch activated in adolescence turns on both BPD and substance abuse in these youngsters. That's something that we are currently investigating in genetic and neuroimaging studies of this group."
He adds that clarifying whether bipolar disorder begins before substance abuse starts could have "a huge impact. If BPD usually precedes substance abuse, there may be intervention points where we could reduce its influence on drug and alcohol abuse. Aggressive treatment of BPD could cut the risk of substance abuse, just as we have shown it does in ADHD." Wilens is an associate professor of Psychiatry at Harvard Medical School.
The National Institute of Mental Health is supporting the long-term study of bipolar youth of which this report is one phase. Co-authors of the Drug and Alcohol Dependence article are Joseph Biederman, MD, Joel Adamson, Aude Henin, Stephanie Sgambati, Robert Sawtelle, Alison Santry and Michael Monuteaux, ScD, MGH Pediatric Psychopharmacology; and Martin Gignac, MD, University of Montreal.
Massachusetts General Hospital (www.massgeneral.org), established in 1811, is the original and largest teaching hospital of Harvard Medical School. The MGH conducts the largest hospital-based research program in the United States, with an annual research budget of more than $500 million and major research centers in AIDS, cardiovascular research, cancer, computational and integrative biology, cutaneous biology, human genetics, medical imaging, neurodegenerative disorders, regenerative medicine, systems biology, transplantation biology and photomedicine.