Peripheral sub-inflammation is associated with antidepressant consumption in schizophrenia. Results from the multi-center FACE-SZ data set.

OBJECTIVES: The relation between C-Reactive Protein (CRP), depression and antidepressant consumption has been well explored in major depressive disorders but not in schizophrenia, which has a high rate of depression comorbidity. The objectives of this study were: (i) to determine the prevalence of abnormal CRP levels, depression and antidepressant consumption in a multicenter community-dwelling sample of subjects with schizophrenia (ii) to determine the association between abnormal CRP levels, depression and antidepressant consumption in schizophrenia.

METHOD: 219 stable patients with schizophrenia (mean age=31.6 years, 75.3% male gender) were systematically included in the multicentre network of FondaMental Expert Center for schizophrenia (FACE-SZ) and assessed with a dedicated electronic medical record including the Structured Clinical Interview for DSM-IV Axis I Disorders and Calgary Depression Scale for depression. High sensitivity CRP (hs-CRP) was measured with an assay using nephelometry (Dade Behring). Abnormal CRP level was defined by levels >3mg/L. Current medication was recorded.

RESULTS: Overall, 63 subjects (28.8%) were found to have abnormal CRP levels, 43 (20.1%) received a diagnosis of comorbid current depression, and 51 (31.9%) had ongoing antidepressant treatment. In univariate analysis, abnormal CRP levels were found to be significantly associated with body mass index (BMI) (p<0.0001), hypertriglyceridemia (p=0.0015), high waist circumference (p<0.0001), metabolic syndrome (p=0.0011), abdominal obesity (p0.05). In a multivariate model, abnormal CRP was associated with antidepressant consumption independently of other confounding variables (adjusted Odds Ratio=2.8, 95% confidence interval 1.22-6.62). Metabolic syndrome was also independently associated with abnormal CRP (adjusted Odds Ratio=2.6, 95% confidence interval 1.01-6.71).

CONCLUSION: Abnormal CRP levels in schizophrenia were found to be associated with antidepressant consumption, but not with depression. The potential mechanisms were discussed. Antidepressant consumption should be systematically recorded in future studies exploring inflammation in schizophrenia. Future clinical trials of interventions directed at lowering the level of CRP and other inflammatory markers are discussed.