Lack of association between clinical and cognitive change in first-episode psychosis: the first 6 weeks of treatment.

OBJECTIVE

To investigate potential changes and associations in clinical dimensions and cognitive functioning after the first 6 weeks of pharmacological treatment as the relation between cognitive and clinical change may have an impact in determining the importance of cognition as a treatment target.

METHOD

Patients (n = 42) completed a brief battery of 5 neurocognitive tests within 72 hours of commencing, and 6 weeks after, standard pharmacological treatment. The cognitive testing comprised 5 domains: attention, visuomotor speed, declarative memory, working memory, and executive function. Volunteers (n = 43) were recruited to control for practice effects.

RESULTS

Patients and control subjects improved over time in the raw scores in cognitive tests. Patients' performance, at baseline and end point assessments, was below that of the control subjects in all cognitive variables, except the Stroop interference score. No interaction effect between time and group was found. Further, after controlling for practice effects and adjusting for multiple comparisons, patients' cognitive performance showed no significant improvement. Accordingly, there was no association between clinical improvement and cognitive change. This lack of association was also observed in the subgroup of people who showed decreased scores in negative symptoms.

CONCLUSION

Cognitive response is not clearly enhanced by antipsychotic drugs and it is not a by-product of clinical recovery during the acute phase (first 6 weeks) of a first-episode nonaffective psychosis.