1. Schizophrenia is a group of disorders with heterogeneous causes and unknown exact etiology. It has a worldwide prevalence of 0.6-1.9% and peak onset ages of 10-25 for males and 25-35 for females. 2. The etiology involves genetic, biological, neurological, environmental, and psychosocial factors. The stress-diathesis model integrates these factors. Dopamine dysfunction and abnormalities in brain structures like the limbic system are also involved. 3. Diagnosis is based on DSM-IV criteria including two or more symptoms such as delusions and hallucinations lasting at least 6 months along with social and occupational dysfunction. Treatment involves antipsychotic medication,