Inflammation in psychotic disorders: a population-based study.

We investigated inflammatory markers in psychotic disorders and their association with metabolic comorbidity, antipsychotic medication, smoking, alcohol use, physical condition, and mood. From the population-based Finnish Health 2000 study, we identified all persons with schizophrenia (n=45), other nonaffective psychosis (ONAP) (n=57), affective psychosis (n=37) and chose controls matched by age, sex, and region of residence. We found that persons with schizophrenia had significantly higher sIL-2Rα, IL-1RA and C-reactive protein (CRP), persons with ONAP significantly higher IL-1RA and CRP and persons with affective psychosis almost significantly higher TNF-α compared to their matched controls. Current antipsychotic use was associated with elevated IL-1RA and CRP. After taking metabolic and lifestyle-related variables that associated with inflammatory markers into account, only antipsychotic medication remained associated with elevated IL-1RA and TNF-α which are markers related to the activation of innate immune system. CRP was influenced by both antipsychotic medication and nonaffective psychosis. sIL-2Rα, a marker of T-cell activation, was associated with depressive symptoms, schizophrenia, and affective psychosis. We conclude that in persons with psychotic disorders, activation of mononuclear phagocyte system was mostly related to metabolic comorbidity and antipsychotic medication use, whereas T-cell activation had a more direct relationship with both psychotic disorders and depressive symptoms.