Bipolar disorder in children is an affliction in which the child's mood shifts between mania (high mood) and depression (low mood). The National Institute of Mental Health (NIMH) says that when bipolar disorder is diagnosed during childhood, it's considered early-onset bipolar disorder; children with bipolar disorder have more severe symptoms than older teenagers and adults, and have more mood swings. The cause of pediatric bipolar disorder isn't known, though genetics, abnormal brain structure and preexisting anxiety disorders are possibilities.
Mania
One part of bipolar disorder is mania, which the Child and Adolescent Bipolar Foundation says is defined by euphoria and grandiosity. When a child is in the mania phase of bipolar disorder, she can be more talkative and have racing thoughts. The child is also more irritable, especially if her requests aren't fulfilled by her parents. Poor judgment is also possible, with the child participating in risky behaviors. The child may not sleep as much during the night but doesn't have daytime sleepiness. In some cases, the child can have hallucinations (seeing or hearing things that are not there) or psychosis.
Depression
The other part of bipolar disorder is depression, which the Child and Adolescent Bipolar Foundation says is defined as a lack of joy in life. The child withdraws from other people and activities during depression, and is prone to crying spells. Agitation and concentration problems are also symptoms of depression. The child may have sleeping problems, either oversleeping or insomnia, and may also have fatigue. Appetite changes and subsequent weight changes can also occur. In severe incidents, the child can have thoughts about death and may attempt suicide.
Other Warning Signs
The Child and Adolescent Bipolar Foundation says parents may notice other warning signs of bipolar disorder that don't fit under mania or depression symptoms. Warning signs include sexual behavior that is inappropriate for the child's age, and explosive anger. If the child is bipolar, she might have severe separation anxiety, compulsive cravings and boss around adults. A serious sign is when the child draws or tells stories that contain very graphic violence. Parents who are unsure whether their child's behavior is normal or age-appropriate should talk to their pediatrician.


