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| Representative picture of schizophrenia |
Definition of Schizophrenia:
Schizophrenia is a chronic, severe psychiatric disorder characterized by disturbances in thought, perception, emotion, and behavior, with a significant decline in functioning. It is classified under psychotic disorders.
Etiology of Schizophrenia:
• Genetic: High heritability (~80%). Risk increases with genetic proximity.
• Neurodevelopmental factors: Prenatal infections, obstetric complications, hypoxia.
• Neurotransmitter hypothesis:
• Dopamine hypothesis: Hyperactivity of dopaminergic pathways, particularly mesolimbic (positive symptoms); hypoactivity in mesocortical pathway (negative symptoms).
• Other neurotransmitters: glutamate (hypofunction), serotonin (5-HT2A involvement).
• Psychosocial factors: Urban upbringing, childhood trauma, high expressed emotion in families.
Clinical Features of Schizophrenia:
Symptoms divided into positive, negative, and cognitive:
• Positive symptoms: Delusions, hallucinations (esp. auditory), disorganized speech and behavior.
• Negative symptoms: Avolition, alogia, anhedonia, affective flattening, asociality.
• Cognitive deficits: Impaired attention, working memory, and executive function.
Diagnostic Criteria (DSM-5) of Schizophrenia:
At least 2 of the following for ≥1 month (1 must be from 1–3):
1. Delusions
2. Hallucinations
3. Disorganized speech
4. Grossly disorganized or catatonic behavior
5. Negative symptoms
Duration of illness ≥6 months including prodromal or residual symptoms.
Subtypes of Schizophrenia(no longer in DSM-5, but clinically relevant):
• Paranoid
• Disorganized
• Catatonic
• Undifferentiated
• Residual
Investigations of Schizophrenia:
• Clinical diagnosis
• Neuroimaging (enlarged ventricles, reduced cortical volume)
• Neuropsychological testing
• Rule out secondary causes (e.g., substance use, CNS pathology)
Management of Schizophrenia:
• Pharmacotherapy:
• First-generation antipsychotics (FGAs): e.g., haloperidol, chlorpromazine
• Second-generation antipsychotics (SGAs): e.g., risperidone, olanzapine, clozapine (treatment-resistant cases)
• Psychosocial interventions: CBT, social skills training, family therapy, supported employment
• Rehabilitation: Community support, psychoeducation
• ECT: In treatment-resistant catatonia or severe depression with psychosis
Prognosis of Schizophrenia:
• 1/3 improve significantly
• 1/3 show partial improvement
• 1/3 have chronic course
Poor prognostic factors: early onset, insidious onset, prominent negative symptoms, poor premorbid functioning
