Behavior disorders are characterized by a pattern of aggressive or disruptive behavior that lasts longer than six months, and the behavior is also typically age-appropriate. A teenager or adolescent may act out due to stress or a change in their family or school dynamic. Changing schools, bullying, a move to a new family, divorce, a new sibling, abuse or family conflicts can cause behavior disorders that result in truancy, substance abuse, trouble with the law, and mental health disorders. Because the brain's executive learning and decision making area is not yet fully developed, adolescents and teenagers are still developing mature coping skills and often engage in risky behaviors. Brain damage, malnutrition, and genetics can also contribute to behavior disorders. Although it commonly develops in children or adolescents, behavioral disorders can manifest at any age. Early signs of behavioral problems include drastic changes in personality or behavior, anger, irritability, frequent outburst or tantrums, feelings of sadness, and intense worry. Other signs include social withdrawal or isolation, damaging or destroying property, lying or stealing, weight fluctuations, disregard for hygiene and appearance, and more.