Description

• Major psychiatric disorder characterized by prodrome, active and residual symptoms involving disturbances in appearance, speech, behavior, and perception/thinking that last for at least 6 months.
• The 5 types of schizophrenia: Paranoid, disorganized, catatonic, undifferentiated, and residual (1)
• System(s) affected: Nervous

Epidemiology

• 7.7–43/100,000 (2)
• Predominant age: Onset typically <45 years
• Predominant sex: M:F, 1.4:1.0 (2); onset earlier in males (early to mid-20s) than females (late 20s)

• Lifetime (1%): Highest prevalence in lower socioeconomic classes and urban centers (2-fold higher risk)
• 1.1% of the population >18 years; similar rates in all countries

Risk Factors

Genetics
Biologic relative with schizophrenia: If 1st-degree relative, risk is 8–10%, a 10-fold increase (3)[B].

General Prevention

• Currently, no known preventive measures decrease the incidence of schizophrenia.
• Interventions to prevent some of the associated comorbid conditions and to improve the long-term course and outcome are employed as approaches to prevention.

Etiology

• Unknown: Not initiated/maintained by an organic factor
• Probably a complex interaction between inherited and environmental factors

Commonly Associated Conditions

• Substance use disorders and nicotine dependence are common and lead to significant long-term medical and social complications (4).
• Metabolic syndrome, diabetes mellitus, obesity, and certain infectious diseases, including HIV, hepatitis B, and hepatitis C all occur in higher-than-expected rates in individuals with schizophrenia.