Psychosis is characterized by an altered perception of reality and delusions or hallucinations. Psychosis can manifest as a discrete episode or be a recurrent feature of a psychotic disorder. The symptoms can vary greatly in onset and duration. The disorder most often manifests between the age of 18 and 40 but psychosis can occur throughout life. Around half of those with a psychotic disorder are diagnosed with schizophrenia. Schizophrenia is a chronic disorder characterized by recurrent psychotic episodes but also by depression like symptoms and cognitive deficits. A number of genetic and environmental risk factors have been described but our knowledge on the pathophysiology and etiology of psychotic disorders remains incomplete. We work close to the clinical setting to arrive at new knowledge that can lead to improved diagnostics, treatment and quality of life for those affected by a psychotic disorder.