Assessment of cognitive domains in major depressive disorders using the Cambridge Neuropsychological Test Automated Battery (CANTAB): Systematic review and meta-analysis of cross-sectional and longitudinal studies

Cognitive difficulties are known to persist after remission of symptoms and to affect psychosocial functioning and quality of life. Cognitive function, measured with the Cambridge Neuro-psychological Test Automated Battery (CANTAB), is a reliable approach to measure cognitive function in major depression. This systematic review and meta-analysis appraise cross-sectional and longitudinal studies that used specific CANTAB tests to measure cognitive function in major depression and the effect of treatment (PROSPERO ID: CRD42022355903). 1212 studies were identified and 41 were included, 1793 patients and 1445 healthy controls. Deficits in executive functions were detected with the Stocking Of Cambridge (SOC) ‘number of problems solved with minimal number of moves’ and ‘subsequent thinking time’, Intra-Extra Dimensional Set Shift ‘number of trials to complete the test’, Spatial Working Memory ‘strategy score’ and ‘between errors score’, Spatial Span. Memory deficits were detected with Paired Associates Learning ‘number of total errors’, Pattern Recognition Memory (PRM) ‘% of correct answers’ and ‘response latency’, Spatial Recognition Memory ‘% of correct answers’, Delayed Matching To Sample (DMS) ‘% of total responses’. Impaired attention was detected by Rapid Visual Information Processing ‘response latency’ and probability to detect target’. Mental and motor responses increased when Reaction Time was measured. SOC ‘number of problems solved with minimal number of moves', PRM ‘response latency’ and DMS ‘% of total responses' improved after a course of treatment. A range of variables including year of publication, age, IQ, severity and duration of illness influenced cognitive changes. The presence of significant cognitive deficits requires novel targeted interventions.