The relationship between cognitive impairment in schizophrenia and metabolic syndrome: a systematic review and meta-analysis.

BACKGROUND: Individuals with schizophrenia are at greater risk for metabolic syndrome (MetS) which is associated with cognitive deficits in the general population. MetS might be potentially an important contributing factor to cognitive impairment in schizophrenia.

METHOD: In the current systematic review and meta-analysis, the findings of 18 studies investigating the association between MetS (and its components) with cognitive impairment in schizophrenia are reviewed.

RESULTS: Co-morbidity of MetS (d = 0.28) and diabetes mellitus (d = 0.28) were both associated with more severe cognitive deficits in schizophrenia. There was also evidence for a significant relationship between cognitive impairment in schizophrenia and each of the components of MetS including hypertension, dyslipidemia, abdominal obesity and diabetes.

CONCLUSIONS: MetS is significantly associated with cognitive impairment in schizophrenia and can potentially contribute to functional decline observed in some patients with schizophrenia throughout the course of illness.