Three-Year Follow-up of a Randomized Controlled Trial of Cognitive Therapy for the Prevention of Psychosis in People at Ultrahigh Risk

Abstract

There have been recent advances in the ability to identify people at high risk of developing psychosis. This has led to interest in the possibility of preventing the development of psychosis. A randomized controlled trial compared cog- nitive therapy (CT) over 6 months with monthly monitor- ing in 58 patients meeting criteria for ultrahigh risk of developing a first episode of psychosis. Participants were followed up over a 3-year period. Logistic regression dem- onstrated that CT significantly reduced likelihood of being prescribed antipsychotic medication over a 3-year period, but it did not affect transition to psychosis defined using the Positive and Negative Syndrome Scale (PANSS) or probableDiagnostic andStatistical Manualof Mental Dis- orders, Fourth Edition diagnosis. However, exploratory analyses revealed that CT significantly reduced the likeli- hood of making progression to psychosis as defined on the PANSS over 3 years after controlling for baseline cognitive factors. Follow-up rate at 3 years was 47%. There appear to be enduring benefits of CT over the long term, suggesting that it is an efficacious intervention for people at high risk of developing psychosis. chosis. Yung and colleagues1 from the personal assess- ment and crisis evaluation (PACE) clinic in Melbourne developed operational criteria to identify 4 subgroups at ultrahigh risk of incipient psychosis, which they termed at-risk mental state (ARMS); these consisted of attenu- ated psychotic symptoms (AS), brief limited intermittent psychotic symptoms (BLIPS), a first-degree relative with a psychotic disorder in combination with a deterioration in the patient's functioning, and schizotypal personality disorder in combination with a deterioration in the patient's functioning. They found that 40% of this high- risk sample became psychotic over a 9-month period. The identification of risk factors that yield such a high- risk group suggests the possibility of using preventative interventions. It has been reported that specific pharma- cotherapy and psychotherapy reduced the risk of early transition to psychosis in young people at ultrahigh risk, in comparison with supportive therapy and case manage- ment, with a reduction in progression to psychosis at end of treatment, but not at 6-month follow-up.2 This finding was interpreted as a delay in onset, rather than prevention. However, a recent study demonstrated that a psychological intervention alone (cognitive therapy (CT)) appeared to re- duce transition to psychosis at 12-month follow-up in a ran- domized controlled trial of 58 people who met ARMS criteria.3 This report from the same study aims to deter- mine whether psychological intervention could prevent, in the long term, transition to psychosis in help-seeking individuals at operationally defined high risk. We hypoth- esized that, at 3-year follow-up, a 6-month course of CT would continue to show significant reductions in the tran- sition rate to psychosis in comparison to a monitoring alone control group. In addition, we hypothesized that tak- ing into account factors that are hypothesized, mechanisms of change in CT would improve prediction.