Chapter 2 Memory impairment in schizophrenia

We present meta-analyses of the published literature on recall and recognition memory performance in patients with schizophrenia compared with normal controls. Tests of categorical models were used in analyses of potential moderators (clinical variables and study characteristics). Our findings (integrating the results of 70 studies) reveal a significant and stable association between schizophrenia and memory impairment. The composite effect size for recall performance was large, d=1.21. Recognition showed less, but still significant, impairment, d=0.64. The magnitude of memory impairment was not affected by age, medication, duration of illness, patient status, severity of psychopathology or positive symptoms. Negative symptoms showed a small, but significant relation with memory impairment. In conclusion, this meta-analysis documents significant memory impairment in schizophrenia. The impairment is stable, wide ranging and not substantially affected by potential moderating factors such as severity of psychopathology and duration of illness. During the last decades, evidence has accumulated that schizophrenia is associated with significant impairment in cognitive functioning. Specifically, deficits in attention, memory and executive functions have been consistently reported in patients with