Cognitive dysfunction in schizophrenia and bipolar disorder – pathophysiological insights and implications for treatment

Abstract

Impaired information processing is a core feature of both bipolar disorder and schizophrenia, which are part of a continuum of neurodevelopmental disorders. This is underscored by the presence of pervasive cognitive impairments affecting both basic perceptual and higher-order cognitive domains. Given that these deficits are important determinants of long-term functional outcome, the current lack of effective treatment options constitutes a major unmet need. Progress is impeded by our limited knowledge about the underlying mechanisms. Visuospatial working memory (VWM) and attention are two intricately and bi-directionally linked cognitive domains for essential elucidating the basis of perturbed information processing in schizophrenia and bipolar disorder. In line with the neurodevelopmental continuum model, I will present data indicating the presence of a transdiagnostic gradient of cognitive impairment in these domains, with patients with schizophrenia being more affected. Jointly studying both VWM and attention can also identify islands of preserved cognitive processes, which can provide important constraints for neurophysiological models of cognitive dysfunction and guide the development of pro-cognitive interventions. I will also discuss the relevance of basic visual processing deficits for impairments in VWM and attention. Moreover, imaging genetics data implicating the visual system in schizophrenia resilience mechanisms suggest that focusing on visual dysfunction might be key for the development of novel preventative interventions during the early stages of illness.