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:

– to determine the prevalence of abnormal CRP levels, depression and antidepressant consumption in a multi-center community-dwelling sample of subjects with schizophrenia;

– to determine the association between abnormal CRP levels, depression and antidepressant consumption in schizophrenia.

Two hundred and nineteen 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 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.

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 metabolic syndrome (P=0.0011) and with antidepressant consumption (P=0.01), while depression, psychotic symptomatology, age of onset, illness duration, sociodemographic characteristics, current tobacco or cannabis status were not (all P>0.05).

In a multivariate model, abnormal CRP was highly associated with antidepressant consumption independently of other confounding variables (adjusted odd ratio=2.9, 95% confidence interval 1.2–6.8).

Abnormal CRP levels in schizophrenia were found to be associated with antidepressant consumption, but not with depression.