Bipolar disorder is characterized by changing mood states, alternating between depression and mania. Children manifest symptoms of the disorder somewhat differently than adults, tending to demonstrate a combination of depression and mania at the same time, known as mixed episodes, and they cycle more rapidly between mood states. Although the prevalence in children is unknown, bipolar disorder that begins in childhood tends to be more severe than that diagnosed in adulthood. The causes of the disorder are thought to involve a combination of biology, brain structure and environment.
Genes
A diagnosis of bipolar disorder is more common in children with family members who have the disorder. The National Institute of Mental Health reports that a child whose parent or sibling has been diagnosed has a significantly increased risk, four to six times higher, of diagnosis himself. Although children whose family members have been diagnosed with bipolar disorder are at greater risk, the majority still will not develop the disorder, indicating that other factors besides inherited genes are at play.
Differences in Brain Composition
As described by Robert Weis, author of "Introduction to Child and Adolescent Psychology," the brains of children with bipolar disorder work differently. There are differences in the structure of certain brain regions, including the thalamus, frontal cortex and limbic system. The frontal cortex is important in planning and organizational skills, but shows less activity in children with bipolar disorder. Both the thalamus and limbic system are critical to emotional processing. These brain areas in children with bipolar disorder are often overly active in processing and the structures themselves are smaller. These differences in brain composition lead to a lessened ability to organize and plan, with an overactive emotional regulation system, leading to difficulty controlling and regulating mood.
Environment
Certain life events are also thought to impact the development of bipolar disorder. According to Weis, family conflict and severe stress in a child's environment can lead to the development of bipolar symptoms. Also, disrupted routines and sleep habits can alter a child's ability to manage mood, which can lead to the development of bipolar symptoms as well.
Anxiety Disorders
According to the National Institute of Mental Health, children who have an anxiety disorder are more likely to later develop bipolar disorder. However, they note that anxiety disorders are common in children, but the majority does not develop bipolar disorder.
References
- National Institute of Mental Health: What affects a child's risk of getting bipolar disorder?
- "Introduction to Abnormal Child and Adolescent Psychology"; Robert Weis; 2008
