3. Study design We will use a prospective, randomized, double-blind, placebo-controlled, single-centre study design. Eighty one individuals aged 13-25 will be randomly assigned in two treatment conditions at the University Clinic for Child and Adolescent Neuropsychiatry, Vienna, Austria. Randomization codes will be generated and stored off site. The treatment groups will receive 1.2 gramm per day EPA/DHA or placebo for 12 weeks. Follow-up assessments will be conducted at 1,2,3,4,8,12,26,and 52 weeks. All patients will receive standard treatment, which includes management by a psychiatrist or resident psychiatrist and non-neuroleptic pharmacotherapy as clinically indicated.