Course of cognitive functioning in first-episode psychosis: a comparison between schizophrenia and non schizophrenia psychosis.

Aims: To describe the course of cognitive functioning in first-episode psychosis and to determine possible differences in the degree and trajectory of cognitive deficits between schizophrenia and non-schizophrenia first-episode psychosis.

Method: We assessed attention, working memory, and executive functioning in 57 patients with first-episode psychosis both at baseline and at 1-year of follow-up.

Results: For the overall group, significant reductions were found in the percentage of omission and commission errors for the sustained attention task (p<0.001 and p=0.001, respectively), in the total time to complete the Stroop-I task (p<0.001), in the percentage of omission errors for the working memory task (p=0.001), and in the percentage of perseverative errors for the Wisconsin card sorting test (WCST; p<0.001), as well as a significant increase in the number of categories completed in the WCST (p<0.001). The remaining cognitive variables analyzed remained stable (4 of the 10 variables tested). The pattern of change was similar for patients with schizophrenia (n=20) and non-schizophrenia (n=37) in the areas of attention and working memory. For executive functioning, the non-schizophrenia group showed a more beneficial pattern of change. No significant differences were detected in cognitive performance among subgroups at baseline or at the 1-year follow-up.

Conclusion: The course of cognitive deficits in first-episode psychosis showed significant improvements over the 1-year period in the areas of attention, working memory and executive functioning. Neuropsychological performance did not seem to be specific enough to distinguish between patients with schizophrenia and non-schizophrenia first-episode psychosis, at least during the first year.