Schizophrenia is a serious mental health problem that affects about one percent of any population. For some people it can become an illness that they have to live with for their entire life. Early research has suggested that supplementing the diet with omega 3 or omega 6 fatty acids may have a positive effect on the symptoms of schizophrenia. This review looks at randomised control trials where omega 3 or omega 6 were used in combination with antipsychotic medication, or as a treatment in their own right for schizophrenia. Eight studies were found which included a total of 517 people who had a diagnosis of schizophrenia or schizoaffective disorder (combined symptoms of schizophrenia and a mood disorder). They ranged from six to 16 weeks in length and were in both hospital and community settings.