Cognitive aging effects in schizophrenia: A quantitative review

Cognitive impairments are well-established in schizophrenia; however the impact of the aging process on cognition is controversial. Meta-analytic techniques were used to quantify the impact of aging in patients with schizophrenia on long-term memory (LTM). Fifty verbal memory effects from 49 studies and 30 non-verbal memory effects from 29 studies were identified with participants falling into the following age ranges: young (20- 39), middle-aged (40-59), and old (60-79). Relative to controls, the oldest patient samples demonstrated greater LTM impairments for both verbal (d=- 1.87) and non-verbal (d=- 1.56) material. Middle-age patient samples showed equivalent impairments to that of young patients in verbal LTM (d=-1.02 and -1.14 respectively), but greater impairments in non-verbal LTM (d=-1.38 vs. -0.91). In conclusion, these results demonstrate that older patients with schizophrenia are significantly more impaired in LTM than younger patients and suggest that schizophrenic patients may be at increased risk for cognitive decline in late-life.