Effects of Cognitive Remediation on Cognition in Young People at Clinical High Risk of Psychosis

Onset of psychotic disorders such as schizophrenia, typically occurs during late adolescence or early adulthood often resulting in chronic social and occupational disability. Deficits in cognition and functional outcome often precede the onset of full-blown psychosis although to a lesser degree than observed in schizophrenia. Recent progress in risk identification methodology has enabled reliable detection of persons who appear to be putatively prodromal for psychosis, that is, at clinical high risk (CHR) of developing a psychotic disorder. Since these CHR individuals already evidence cognitive deficits, which increase around the time of conversion, cognition is an excellent treatment target. Furthermore, there is clear evidence, in schizophrenia and in CHR samples, that deficits in cognition are related to poor functional outcome. Thus, treatments targeting cognition may consequently improve functional outcome. The primary aim of the project is to reduce cognitive deterioration and improve cognition among youths at CHR using cognitive remediation and to test the effectiveness of a new cognitive remediation program, the Brain Fitness program, in improving cognition of CHR individuals. A control treatment consisting of video games (VG) will be used. The primary hypothesis is that the BF group will have improved cognition at the end of treatment and 12 months post baseline compared to the VG group. A secondary hypothesis is that improved cognition will be associated with improved functioning. This is a longitudinal, single blind, placebo controlled pilot trial of cognitive remediation in 36 CHR persons. Participants will be randomised to either the BF or VG program, which will be administered over a period of 3 months. Assessments will occur at baseline, post treatment (3 months) and at 12 months after baseline. All subjects will be recruited in year 1 of the project and treatment will be completed by 15 months. The 40 hours of training will occur 4 days a week, for an hour each day, over a period of 10 -12 weeks.

Participants were randomised to either the BFP or a control treatment consisting of commercial computer games (CG). Participants were not blind to group allocation but all cognitive and symptom raters were. The 40 hours of BFP or computer game activity was expected to occur 4 days a week, for an hour each day, over a period of 10-12 weeks. The primary outcome was cognitive function assessed using the MATRICS consensus cognitive battery MCCB) (Nuechterlein and others 2008). The secondary outcome was social and role functioning assessed with Global Functioning: Social and Role scales. All clinical and cognitive assessments using symptom, functioning and cognitive measures were performed at baseline, post-treatment (at 3 months) and at 9-month follow-up (i.e. 9 months post baseline or 6 months after post-treatment assessment).