OBJECTIVE: To investigate whether using ecstasy (3,4-methylenedioxymethamphetamine, MDMA) is preceded by symptoms of behavioural and emotional problems in childhood and early adolescence. DESIGN: Prospective, longitudinal, population based study SETTING: The Dutch province of Zuid-Holland. PARTICIPANTS: A sample of 1580 individuals, followed up across a 14 year period, from childhood into...
To investigate if associations between cannabis use and psychotic symptoms occur independently, or occur as a consequence of previous-other types of-psychopathology. A 14-year follow-up study of 1580 initially 4- to 16-year-olds who were drawn randomly from the Dutch general population was conducted. At initial assessment, psychopathology was assessed with the Child Behavior Checklist. Across...