Mortality in schizophrenia: clinical and serological predictors

Area of Science:

• Psychiatry and Immunology
• Public Health and Epidemiology

Background:

• Schizophrenia is associated with reduced life expectancy, primarily due to natural causes.
• Cigarette smoking and antipsychotic medications are known risk factors for mortality.
• The impact of infectious agents on mortality in schizophrenia requires further investigation.

Purpose of the Study:

• To prospectively assess demographic, serological, and clinical predictors of natural cause mortality in a cohort of individuals with schizophrenia.
• To investigate the role of antibodies to human herpes viruses and Toxoplasma gondii in mortality.
• To identify modifiable risk factors for improving survival rates.

Main Methods:

• Prospective cohort study of 517 individuals with schizophrenia.
• Clinical evaluation and blood sample collection for serological testing (antibodies to Epstein-Barr virus, Herpes Simplex virus type 1, Toxoplasma gondii).
• Mortality data obtained from the National Death Index over an 11-year follow-up period.

Main Results:

• A total of 25 (5%) participants died from natural causes, with a standardized mortality ratio of 2.80.
• Independent predictors of natural cause mortality included cigarette smoking (RR=4.66), lower cognitive score (RR=0.96), elevated antibodies to Epstein-Barr virus (RR=1.22) and Herpes Simplex virus type 1 (RR=1.19), immunologic disease (RR=3.14), and genitourinary disease (RR=2.70).
• Cigarette smoking conferred a nearly 5-fold increased risk of mortality.

Conclusions:

• Cigarette smoking is a major, modifiable risk factor for premature death in schizophrenia.
• Elevated antibodies to Epstein-Barr virus and Herpes Simplex virus type 1 are significant predictors of mortality.
• Interventions targeting smoking cessation and potentially managing viral infections are crucial for improving longevity in this population.