A randomized controlled trial of cognitive behavioral therapy for individuals at clinical high risk of psychosis

There has been increasing interest in early detection during the prodromal phase of a psychotic disorder. To date a few treatment studies have been published with some promising results for both pharmacological treatments, using second generation antipsychotics, and psychological interventions, mainly cognitive behavioral therapy. The purpose of this study was to determine first if cognitive behavioral therapy (CBT) was more effective in reducing the rates of conversion compared to a supportive therapy and secondly whether those who received CBT had improved symptoms compared to those who received supportive therapy.

Fifty-one individuals at clinical high risk of developing psychosis were randomized to CBT or a supportive therapy for up to 6 months. The sample was assessed at 6, 12 and 18 months post baseline on attenuated positive symptoms, negative symptoms, depression, anxiety and social functioning.

Conversions to psychosis only occurred in the group who received supportive therapy although the difference was not significant. Both groups improved in attenuated positive symptoms, depression and anxiety and neither improved in social functioning and negative symptoms. There were no differences between the two treatment groups. However, the improvement in attenuated positive symptoms was more rapid for the CBT group.

There are limitations of this trial and potential explanations for the lack of differences. However, both the results of this study and the possible explanations have significant implications for early detection and intervention in the pre-psychotic phase and for designing future treatments.