Objective: Long-term use of ecstasy is known to be a risk factor for structural brain damage and psychosis. Most patients suffering from ADHD in childhood will not develop psychosis during adulthood but the risk is increased when there is concomitant significant drug use. However, it is difficult to distinguish between substance-induced psychoses with schizophrenic psychosis. Method: We report a case of a patient with history of ADHD who was untreated, who later developed psychotic symptoms soon after initiation of ecstasy uses. The symptoms persisted despite in a ‘drug-free period’ and intensified while on the ecstasy. Results: Present case helps to understand common neurobiological mechanism behind psychosis and brain atrophy, and risk factors such as ADHD and ecstasy abuse. Conclusion: More research in this area is vital for management and further understanding on the importance of treating ADHD earlier and to be more vigilant in establishing the history of substance use.