Attention deficit/hyperactivity disorder (ADHD) is a worldwide and highly prevalent disorder neurobiological disorder which affects affect 5–10% of children. Controlled prospective follow-up studies on ADHD have demonstrated persistence of symptoms into adolescence in 60-85% of individuals diagnosed in childhood (Weiss et al., 1971; Hechtman, Weiss, 1983; Barkley, 1990; Hechtman, 1985,1989,1992, 2000). Hechtman and Weiss were among the first to conduct controlled, prospective follow-up studies of children with ADHD into adulthood (Weiss et al, 1978; Hechtman et al, 1986).

Author has reviewed these most important studies for the establishment of the entity ADHD in adults.

ADHD in adulthood is a prevalent condition which is highly comorbid and causes significant social, occupational and/or emotional functional impairment.

A recent epidemiological study, The National Comorbidity Survey of 10,000 adults indicated an adult population prevalence of ADHD of 4,4% (Kessler et al, 2005). A similar figure (4%) was obtained by Faraone and Biederman 2005 in a population survey of 966 adults (Faraone&Biederman, 2005).

Specific clinical characteristics of adults with ADHD, diagnostic issues, and comorbidity of ADHD in adults have been discussed in comparison with those in children.

Weiss G, Hechtman L, Perlman T. Hyperactives as young adults: School, employers and self-rating scales obtained during 10 years follow-up evaluation. Am J Orthopsychiatry 1978; 48: 438-445

Faraone SV, Biederman J. What is the prevalence of adult ADHD? Results of a population screen of 966 adults. J of Att Dis 2005; 9(2): 384-391