For high-risk kids, whose parents have been diagnosed with bipolar disorder, a new study shows s a strong link between having subthreshold manic episodes (milder episodes that come close to but do not reach the criteria for bipolar disorder) and the eventual development of bipolar disorder.
The findings also show that children of parents with bipolar disorder have much greater rates of having subthreshold mania or hypomania compared to their peers (13.3 vs 1.2 percent); manic, mixed, or hypomanic episodes (9.2 vs 0.8 percent); and major depressive episodes (32 vs 14.9 percent). While these results, published in the American Journal of Psychiatry, may be unsurprising, they could lead to earlier identification, treatment, and preventive measures.
“Mental health practitioners should carefully assess for short episodes of manic symptoms, major depression, and disruptive behavior disorders in high-risk children, as these are risk factors for the future onset of bipolar disorder,” said senior author David Axelson, M.D., medical director of Behavioral Health at Nationwide Children’s Hospital.
“This may be particularly important if medication is going to be used for treating mood or behavioral symptoms in the child, because some medications might increase the risk of developing mania or psychotic symptoms in someone who is already at very high risk for developing bipolar disorder. Prescribers might choose different medication options, or use lower doses and monitor for problems more closely.”
For the study, researchers followed high-risk children as well as demographically matched children of community parents. Follow-up interviews were completed in 91 percent of the offspring with a mean follow-up duration of 6.8 years.
The findings showed that the cumulative rate of bipolar spectrum disorders at age 21 was 23 percent in the high-risk group, compared to 3.2 percent in the comparison group. The mean age of onset for a bipolar spectrum disorder was 12 years, with the earliest manic episode being documented at eight years.
“Most children who have a parent with bipolar disorder will have a diagnosable psychiatric disorder, such as attention-deficit disorder, oppositional defiant disorder, an anxiety disorder or depression, at some point during their youth,” said Axelson, a professor of clinical psychiatry at Ohio State University.
“However, most children who have a parent with bipolar disorder do not develop bipolar disorder.”
Among the high-risk children who did go on to develop bipolar disorder, nearly all had identifiable mood episodes and other psychiatric disorders before the onset of full-fledged bipolar illness.
“Short, distinct episodes of manic symptoms were the most specific predictor of developing bipolar disorder in high-risk offspring,” Axelson said. “But so far, many children with these short manic episodes have not progressed to full-fledged bipolar disorder.”
“I am continuing to collaborate with researchers on the Pittsburgh Bipolar Offspring Study,” Axelson said. “We expect to find more exciting results that will impact the diagnosis and treatment of high-risk children as we follow the participants into young adulthood.”
Source: Nationwide Children’s Hospital