There is suggestion that early intervention in psychosis might be associated with better outcomes (Norman & Malla, 2001). However, intervention in the pre-psychotic phase has been questioned as, using current criteria, only 20-50% of individuals classified as prodromal develop a psychotic disorder within a 1-2 years period (McGlashan et al., 2001). Treatment agents investigated in the pre-psychotic phase of schizophrenia and other psychotic disorders should, therefore, not have major side effects. This proposal introduces EPA/DHA, two omega-3 essential fatty acids (EFA), as a beneficial and possible preventative therapeutic agent in young people at ultra high-risk for developing a psychotic disorder.