Attention-deficit/hyperactivity disorder, ADHD, develops in childhood but may escape diagnosis until the affected person is an adult. Formerly called attention deficit disorder, or ADD, the disorder can have a huge impact on a person's ability to function at work, home and with friends. The treatment is similar to the treatment for childhood ADHD, although adjustments may be made for adult physiology. ADHD Symptoms The basic symptoms of ADHD at any age are inattentiveness, hyperactivity and impulsiveness. In adults, the signs of ADHD manifest as restlessness, impulsive behavior, difficulty concentrating or focusing, disorganization, mood swings, outbursts of temper and difficulty in completing projects. The disorder may affect relationships and success at work. A diagnosis of adult ADHD requires symptoms that began to childhood, since the disorder doesn't spontaneously develop in adults. Causes of ADHD The specific cause of ADHD remains unknown, but there may be genetic factors involved. Brain changes may also be involved, since scans of the brain show different activity patterns in ADHD patients than in people without the disorder, according to MayoClinic. Environmental exposure to toxins during childhood or in the womb may also play a role. ADHD Treatment The main method of treatment involves using medication to control the symptoms of adult ADHD. Stimulants are commonly used by adults with the disorder, although some stimulants are only approved for use with children, according to the National Institute of Mental Health. Antidepressants may also be used in cases where stimulants are ineffective or bring about too many side effects. Some medications may be inappropriate if the adult is on other medications or has certain health issues common in adults, such as high blood pressure. Psychotherapy is another method of dealing with ADHD in adulthood, especially cognitive behavioral therapy, in which the therapist teaches organizational skills and specific methods of dealing with problem circumstances. ADHD Complications Individuals with untreated adult ADHD often have difficulty holding down a job and maintaining stable relationships. Adult ADHD sufferers are also at higher risk for other mental disorders including mood disorders, anxiety and personality disorders. People with adult ADHD also tend to get into more traffic accidents and are more likely to become involved in criminal activity. Considerations when dealing with ADHD in adults Many individuals with adult ADHD were never diagnosed as children and may be unaware that they have the disorder. Others who were diagnosed early may be able to better adjust to the disorder because they are already on a treatment plan. A few show mild symptoms and others just out-grow the disorder if the treatment is continued.