Relapse and exacerbation of psychotic symptoms were investigated in a prospective study of 88 patients with recent-onset schizophrenia and related disorders. Relapse definitions were derived from expressed emotion and family intervention studies and based on the Brief Psychiatric Rating Scale (BPRS), the Present State Examination, and clinical judgment. Results indicate that research and clinical criteria represent different perspectives on relapse. Clinical criteria provide a validity check that can verify BPRS-rated changes in partially remitted patients.