Cognitive reserve and neuropsychiatric disorders

- Cognitive reserve is an active neural process compensating for neuropathology.
- Current measures of cognitive reserve are confounded.
- Greater education, occupation and leisure activity delays dementia symptom onset.
- Premorbid IQ is a risk factor for young adult mental illness and affects outcomes.
- IQ appears to modify the neurodevelopmental process in schizophrenia.

Cognitive reserve is used to explain individual differences in the use of active processes to preserve cognitive function in the presence of brain pathology. Cognitive reserve is difficult to quantify experimentally and studies rely largely on the use of proxy measures such as premorbid IQ, education and occupation. Nevertheless, powerful longitudinal study designs suggest that premorbid IQ modifies the neurodevelopmental process in schizophrenia and modulates the impact of neurodegeneration in dementia. Evidence from intelligence research suggests that dysfunction of a fronto-parietal network has explanatory power for the effect of cognitive reserve in both disorders.