Computerized neurocognitive test performance in schizophrenia: a lifespan analysis.

OBJECTIVE: Computerized neurocognitive batteries based on advanced behavioral neuroscience methods are increasingly used in large-scale clinical and genomic studies. Favorable construct validity in younger schizophrenia patients has been reported, but not in older patients. New variables afforded by computerized assessments were used to clarify age-associated cognitive impairment across the lifespan.
METHODS: 624 patients with schizophrenia and 624 healthy comparison (HC) subjects age 16-75 completed a 1-2-hour computerized neurocognitive battery (CNB) that assessed abstraction and mental flexibility, attention, working memory, recognition memory (verbal, facial, spatial), language, visuospatial, and emotion processing. Linear mixed effects models tested for group differences in accuracy, response time, and efficiency scores. Contrasts were stratified by age.
RESULTS: 91% of older (45+) and 94% of younger (< 45) groups provided "good" data quality. After controlling for parental education and project, there were significant three-way interactions for diagnosis x domain x age group on all three outcome variables. Patients performed worse than HC across all neurocognitive domains, except in the oldest group of 60+ patients. Age-stratified analyses did not show differences between younger (16-45) and older patients (45-60, 60+), except for the attention domain. Older patients' reduced working memory efficiency was due to worse speed, not accuracy. Older patients were quicker than younger patients in processing emotions.
CONCLUSIONS: Computerized assessments are feasible in large cohorts of schizophrenia patients. There is stable and generalized neurocognitive dysfunction across the lifespan in schizophrenia, albeit with fewer differences in some domains between older patients and HC after age 60. Speed-accuracy tradeoff strategies suggest deceleration of some frontal networks and improvements in speed of emotional processing.