- A diagnosis of adult ADHD according to NICE guidelines i.e. if there was evidence from both the participant and the informant (where available) that 1) the participant met DSM-IV criteria for Adult ADHD both in childhood and adulthood 2) that they experienced at least moderate psychological, social and/or educational or occupational impairment in multiple settings and 3) symptoms occurred in two or more settings including social, familial, educational and/or occupational settings. Participants will have received a diagnosis either from the Adult ADHD Service, Maudsley Hospital, London, UK or another specialist/secondary care service (in this case a copy of the diagnostic report will be required). Participants will either already be attending follow-up clinics, including psychoeducation workshops, or will have been recently referred to the service for medication follow-up or psychological treatment.