There are many different reasons why teens have behavioral problems. Medical problems like bipolar disorder, depression or attention deficit hyperactivity disorder (ADHD) may be present and inadequately treated, as the symptoms of these conditions affect behavior. Teens may be troubled by problems at home, both present and past. If divorce, sexual abuse or violent death lurk in your family's past, that might be an issue. Drug use will also affect his or her behavior. Addressing these concerns may make a real difference for your teen, which means you'll need to see a doctor and consider a range of solutions, including medication and counseling. While working on these issues may help your teen, you shouldn't consider them an excuse for bad behavior, but rather as one of many factors in your situation.