Facial emotion perception in schizophrenia: Does sex matter?

AIM To review the literature on sex differences in facial emotion perception (FEP) across the schizophrenia spectrum. METHODS We conducted a systematic review of empirical articles that were included in five separate meta-analyses of FEP across the schizophrenia spectrum, including meta-analyses that predominantly examined adults with chronic schizophrenia, people with early (onset prior to age 18) or recent-onset (experiencing their first or second psychotic episode or illness duration less than 2 years) schizophrenia, and unaffected first-degree relatives of people with schizophrenia. We also examined articles written in English (from November 2011 through June 2015) that were not included in the aforementioned meta-analyses through a literature search in the PubMed database. All relevant articles were accessed in full text. We examined all studies to determine the sample sizes, diagnostic characteristics, demographic information, methodologies, results, and whether each individual study reported on sex differences. The results from the meta-analyses themselves as well as the individual studies are reported in tables and text. RESULTS We retrieved 134 articles included in five separate meta-analyses and the PubMed database that examined FEP across the schizophrenia spectrum. Of these articles, 38 examined sex differences in FEP. Thirty of these studies did not find sex differences in FEP in either chronically ill adults with schizophrenia, early-onset or recently diagnosed people with schizophrenia, or first-degree relatives of people with schizophrenia. Of the eight studies that found sex differences in FEP, three found that chronically ill women outperformed men, one study found that girls with early-onset schizophrenia outperformed boys, and two studies found that women (including first-degree relatives, adults with schizophrenia, and the healthy control group) outperformed men on FEP tasks. In total, six of the eight studies that examined sex differences in FEP found that women outperformed men across the schizophrenia spectrum. CONCLUSION Evidence to date suggests few sex differences in FEP in schizophrenia; both men and women across the schizophrenia spectrum have deficits in FEP.