Children who have a parent with a bipolar disorder are at increased risk for developing a similar disorder. Most children of a bipolar parent will never develop the disorder but a recent study has identified early warning signs in the children most likely to develop a bipolar disorder.

David Axelson, medical director of Behavioral Health at Nationwide Children’s Hospital in Columbus, Ohio, is the lead author of the study which involved:

• 391 children, 6 to 18 years old, with a bipolar parent (study group).
• 248 children demographically matched to the study group but with no bipolar parent (control group).

Axelson’s research team followed these children for an average of 6.8 years, conducting standardized diagnostic tests to assess their mental state and likelihood of developing a bipolar disorder. By the end of the study, 91% of the original study participants were still actively involved.

The Axelson research team looked for evidence of subthreshold behaviors (less severe than the symptoms that would merit diagnosis) as follows:

Mania or hypomania:

• 13.3% in the study group
• 1.2% in the control group

Manic, mixed, or hypomanic episodes:

• 9.2% in the study group
• 0.8% in the controls

Major depressive episodes:

• 32.0% in the study group
• 14.9% in the controls

Attention deficit hyperactivity disorder:

• 30.7% study group
• 18.1% controls

Disruptive behavior disorders:

• 27.4% study group
• 15.3% controls

Anxiety disorders:

• 39.9% study group
• 21.8% in controls  

Substance use disorders:

• 19.9% study group
• 10.1% controls

Unipolar major depressive disorder (major depression with no manic bipolarity):

• 18.9% in the study group
• 13.7% in the control group

Axelson’s research reveals a stronger likelihood that children in the study group (with a bipolar parent) will experience subthreshold behaviors than their counterparts with no bipolar parent for all disorders except unipolar major depressive disorder. The research team found the difference between groups to be statistically insignificant, indicating both the study and the control groups are at almost equal risk for unipolar major depressive disorder.

Additionally, the researchers found:

• 23% of high-risk children had developed bipolar spectrum disorders at age 21.
• 3.2% of the control group had developed a disorder by age 21.
• 12 was the mean age of onset for bipolar spectrum disorders.
• 8 was the earliest age a child developed a manic episode

Axelson said, "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."

Assessment of these short subthreshold episodes is particularly important, according to Axelson, when medication is prescribed. “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,” he said. He suggests lower doses or different medications may prove to be better options for these at-risk children.


Sources:

1. Axelson, David, et al. "Diagnostic Precursors to Bipolar Disorder in Offspring of Parents With Bipolar Disorder: A Longitudinal Study." The American Journal of Psychiatry. American Psychiatric Association, Mar. 2015. Web. 13 Mar. 2015.
2. "Bipolar Disorder." Mayo Clinic. Mayo Foundation for Medical Education and Research, 10 Feb. 2015. Web. 13 Mar. 2015.