This study consists of two parts: (1) a community survey among 1000 adults to establish the validity of AAQoL; and (2) a case-control study with a sample of 60 adults, aged 18-50, with DSM-IV ADHD and 60 healthy controls matching for the age and sex structure of the ADHD group. The instruments include a standard psychiatric diagnostic interviews using (K-SADS-E), self-administered rating scales for assessing psychopathology (ASRI), ADHD symptoms (ASRS, CGI-ADHD-S,), social and family functions (AAQoL, SDS, Moos dyadic assessment, family APGAR, GDS) and neuropsychological assessment (WAIS-III, CANTAB). The ADHD group will be reassessed for symptom severity and neuropsychological functioning 2-3 months (ranging from 8 to 12 weeks) after the first assessment.