Schizophrenia

Schizophrenia is a chronic, severe mental disorder that affects how a person thinks, feels, and behaves. People with schizophrenia may seem like they have lost touch with reality, which causes significant distress for the individual, their families, and friends. **Symptoms are typically divided into three categories:** **Positive Symptoms** (adding abnormal experiences): - Hallucinations (hearing, seeing, or feeling things that are not there) - Delusions (fixed false beliefs—paranoid, grandiose, or bizarre) - Disorganized speech (jumping between unrelated topics) - Disorganized or abnormal motor behavior **Negative Symptoms** (losing normal functions): - Reduced emotional expression (flat affect) - Decreased motivation (avolition) - Reduced speech (alogia) - Inability to experience pleasure (anhedonia) - Social withdrawal **Cognitive Symptoms:** - Problems with attention and concentration - Working memory difficulties - Problems with executive function (planning, organizing) **Important misconceptions to correct:** - Schizophrenia is NOT "split personality" (that is Dissociative Identity Disorder) - Most people with schizophrenia are NOT violent (they are more likely to be victims) - Schizophrenia IS treatable, and many people live fulfilling lives with proper care

Schizophrenia develops from a complex interaction of genetic and environmental factors: **Genetic factors:** - Strong heritability (about 80%) - If one identical twin has it, the other has ~50% chance - If a parent has schizophrenia, child has ~10% chance - Multiple genes contribute small effects **Brain changes:** - Altered dopamine and glutamate signaling - Reduced gray matter in certain brain regions - Enlarged ventricles - Abnormal connectivity between brain regions **Environmental factors:** - Prenatal complications (infection, malnutrition, stress) - Birth complications - Cannabis use in adolescence (increases risk in vulnerable individuals) - Childhood trauma - Urban environment - Migration stress **The Neurodevelopmental Model:** Schizophrenia is increasingly understood as a neurodevelopmental disorder—brain development goes awry early in life, but symptoms emerge later when the brain matures. Stress and substance use can trigger the first episode in vulnerable individuals.