Pilot study of cognitive remediation therapy on cognition in young people at clinical high risk of psychosis

• We test the efficacy of cognitive remediation therapy (CRT) in improving cognition of CHR individuals.
• Participants are tested at baseline, immediately following CRT and 9 months post-baseline.
• Trend towards improvement in speed of processing between baseline and 9-month follow-up in the experimental group.
• Significant improvements in working memory observed between post-CRT and 9-month follow-up in the control group.
• CRT may be valuable for individuals at CHR but the type of intervention employed needs to be carefully considered.

Individuals at clinical high risk (CHR) of psychosis evidence cognitive deficits. Given suggestions that deficits in cognition are related to poor functional outcome, cognition is a good treatment target. The aim of this study was to test the efficacy of cognitive remediation therapy (CRT) in improving cognition of CHR individuals. Participants were tested at baseline, immediately following CRT and 9 months post-baseline. The mixed effects modelling demonstrated no differences in cognition between the experimental group and the control group at any time point. For the experimental group, however, there was a trend towards improvement in speed of processing between baseline and 9-month follow-up (t(29)=−2.91, P=0.06) and at post-CRT compared to 9-month follow-up (t(29)=−2.99, P<0.05). In the control group, significant improvements in working memory were observed between post-CRT and 9-month follow-up (t(29)=−3.06, P<0.05). Despite significant improvements in social functioning in the intervention group between baseline and 9-month follow-up (t(28)=−3.26, P<0.05), these improvements were not correlated with cognition. There were trends towards improvement and no trends of decline in the two groups. While CRT may be valuable for individuals at CHR, the type of intervention employed needs to be carefully considered.