Patients with schizophrenia and other psychoses experience cognitive decline after illness onset, but the extent of the decline various across cognitive functions, a new study found. Participants were from a population-based case-control study of patients with first-episode psychosis who were followed prospectively up to 10 years after first admission. A neuropsychological battery was administered at index presentation and at follow-up to patients with a diagnosis of schizophrenia (n=65) or other psychoses (n=41), as well as to healthy comparison subjects (n=103). Among the findings:
- The schizophrenia group exhibited declines in IQ and in measures of verbal knowledge and of memory, but not processing speed or executive function.
- The magnitude of declines ranged between 0.28 - 0.66 standard deviations.
- Decline in measures of memory was not specific to schizophrenia and was also apparent in the group of patients with other psychoses.
Zanelli J, et al. Cognitive change in schizophrenia and other psychoses in the decade following the first episode. [Published online ahead of print July 1, 2019]. Am J Psychiatry. doi: 10.1176/appi.ajp.2019.18091088.