A mental illness characterized by repeated episodes of serious violence against people or property that occur with little or no provocation. Relief follows the violent episode, and the individual usually expresses upset, remorse, regret, or embarrassment. Since explosive disorder is very rare, little is known about what causes of the disorder. Similar outbursts can be caused by certain medications, illegal drugs, a serious head injury, epilepsy, Alzheimer’s disease, or by a number of other disorders, such as attention deficit/hyperactivity disorder, mania, or psychosis.