Attention Deficit Hyperactivity Disorder (ADHD) is a chronic condition characterised by the symptoms of inattention, hyperactivity and impulsivity. While these symptoms are normal characteristics experienced by all people at one time or another, among individuals who are diagnosed with ADHD, there is an overabundance of these characteristics. Their levels of overactivity, inattention and/or impulsivity are severe and persistent and interfere with their learning, relationships and work.
While many children and adolescents with ADHD improve as they grow up, many will continue to experience symptoms as an adult. In adulthood the symptoms are typically displayed somewhat differently to the way they are displayed in childhood. A child who squirms, fidgets and is constantly 'on the go' may become an adult who is less obviously physically overactive but experiences intense feelings of restlessness. He or she may have troubling relaxing and may overwork. An impulsive child who blurts out answers in class, who constantly interrupts others and talks excessively may become an adult who displays impatience when in queues or whilst driving, and who may be impulsive with spending or quitting jobs. Inattentive children who have difficulty listening and forget their homework may become adults who often complain of losing things, such as keys and wallets, and are often late for appointments.
Among children affected by ADHD, about one half will predominantly have inattention problems, a quarter will mainly have hyperactive and impulsive symptoms, while the remainder will have a mixture of these symptoms.
It is common for children with ADHD to have co-occurring psychiatric conditions, the most common of which are disruptive behaviour disorders ('oppositional defiant disorder' or ODD - which involves a pattern of arguing with multiple adults, losing one's temper, refusing to follow rules, blaming others, deliberately annoying others, and being angry, resentful, spiteful, and vindictive; and 'conduct disorder' or CD - which is associated with efforts to break rules without getting caught, and may include being aggressive to people or animals, destroying property, lying or stealing, running away, and skipping school), and mood disorders (depression, mania/bipolar disorder and anxiety).