New research reveals a strong association between first degree relatives with psychological disorders such as ADHD and children diagnosed with bipolar I.
ADHD is a common condition, estimated to be present in three to seven percen of school-aged children, and is diagnosed three to five times more often in boys than girls. Symptoms include inattentiveness, restlessness, hyperactivity and impulsivity. Children with ADHD are at increased risk for other conditions such as learning disorders, anxiety, depression, bipolar disorder, and substance abuse disorders.
Bipolar I and bipolar II disorders are differentiated by the presence of mania in bipolar I versus hypomania in bipolar II. One in five new diagnoses of bipolar disorder are made in individuals under the age of 20. In children mania can be more difficult to diagnose, as mania can often look like irritability.
Janet Wozniak and her team from Massachusetts General Hospital conducted a blinded, case-controlled family study to assess the spectrum of risk for psychological disease in children who have with family members with bipolar I and ADHD.
Wozniak studied the association between children diagnosed with bipolar I and first degree relatives. The researchers used structured diagnostic interviews to examine 157 children with bipolar I and 486 of their relatives, 162 children with ADHD and 586 of their relatives, as well as 136 childen without bipolar I or ADHD and 411 of their relatives.
The relatives of children with bipolar I disorder were found to have four times the rate of bipolar I, and the relatives of the children with ADHD were found to have 3.5 times the rate of ADHD compared to the relatives of healthy children. In addition to the increased risk for bipolar I, the relatives of the children with bipolar I also had higher rates of psychosis, depression, anxiety, substance abuse disorders, and ADHD.
There is a widespread perception in both the general public and often even among physicians that the epidemic of mental illness in children may be due to overdiagnosis. These findings help support the legitimacy of the bipolar diagnosis in young children and may encourage parents to seek earlier diagnosis and treatment.
“These results support the validity of the diagnosis of bipolar I in children as defined in the DSM-IV,” writes Wozniak and her co-authors.
“More work is needed to better understand the nature of the association between these disorders.”
While it is possible that family members with psychological illness are more likely to be sensitive to the presence of symptoms in their children, the magnitude of the effect seen in this study makes it seem unlikely that increased awareness could explain the difference in diagnostic rates.