Most child and adolescent mental health services recognise the existence of, and need for treatment in, attention-deficit hyperactivity disorder (ADHD). Many specialist multidisciplinary ADHD clinics have been developed in recent years, and many paediatricians have included the treatment of ADHD as an important part of their clinical activity. A good deal of the justification for this increase in therapeutic activity has been the demonstration that ADHD is indeed a predictor of adult mental health problems. General adult psychiatry, however, has not followed suit in identifying and treating substantial numbers of affected people. It is likely none the less that an increasing load in adult psychiatry will develop. A rising number of young people will enter adult life still receiving stimulant medication or other treatment for ADHD, and adult psychiatrists are likely to be consulted. Furthermore, an increasing number of adults are likely to recognise themselves as having been disabled by ADHD and therefore to seek assistance. In many cases, individuals with adult ADHD who require specific treatment for the condition will have been treated unsuccessfully for disorders with overlapping symptom profiles such as anxiety, depression, bipolar disorder and antisocial personality disorder.