Red blood cell polyunsaturated fatty acids measured in red blood cells and schizophrenia: a meta-analysis.

Alterations of polyunsaturated fatty acids (PUFA) in schizophrenia have been reported, but there is substantial variation in the findings. We performed a systematic review and meta-analysis for docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), linoleic acid (LA), and arachidonic acid (AA). We identified 18 studies which compared PUFA in the erythrocyte cell membrane between patients with schizophrenia and controls. A total of 642 patients (169 were antipsychotic-naïve) and 574 controls participated in these studies. We found suggestive evidence that the levels of DPA (C22:5n3) and DHA (C22:6n3) are decreased both in patients currently being treated with antipsychotic medication and antipsychotic-naïve patients. Our findings furthermore suggest that the levels of LA (C18:2n6) are decreased in the medicated subgroup, but not in the antipsychotic-naive group. Finally, we found decreased levels of AA (C20:4n6), most convincingly in antipsychotic-naive patients. Taken together, there is substantial evidence that decreased levels of DPA (C22:5n3), DHA (C22:6n3), and AA (C20:4n6) are associated with the schizophrenia syndrome, apart from a possible influence of antipsychotic medication. Given the large heterogeneity in results, these conclusions should be interpreted cautiously.