Cognitive decline following psychosis onset: Data from the PACE clinic

Background: The origin of cognitive impairments in psychotic disorders is still unclear. Although some deficits are apparent prior to the onset of frank illness, it is unknown if they progress. Aims: To investigate whether cognitive function declined over the transition to psychosis in a group of ultra-high risk individuals. Method: Participants consisted of two groups: controls ( n=17 ) and individuals at ultra-high risk for development of psychosis ( n=16 ). Seven of the latter group later developed psychosis. Neuropsychological testing was conducted at baseline and again after at least a 12-month interval. Results: Both the Visual Reproduction sub-test of the Wechsler Memory Scale-Revised and Trail-Making Test B showed a decline over the follow-up period that was specific to the group who became psychotic. In addition, both high-risk groups showed a decline in digit span performance. No other task showed significant change over time. Conclusions: These preliminary data suggest that as psychosis develops there may be a specific decline in visual memory and attentional set-shifting, reflecting impairments in efficient organisation of visual stimuli. This may be caused by either the illness itself or treatment with antipsychotic medication.