Randomized Controlled Trial of Interventions Designed to Reduce the Risk of Progression to First-episode Psychosis in a Clinical Sample with Subthreshold Symptoms

Background: Most disability produced by psychotic illnesses, especially schizophrenia, develops during the prepsychotic period, creating a case for intervention during this period. However, only recently has it been possible to engage people in treatment during this phase.

Methods: A randomized controlled trial compared 2 interventions in 59 patients at incipient risk of progression to first-episode psychosis. We termed this group ultra-high risk to emphasize the enhanced risk vs conventional genetic high-risk studies. Needs-based intervention was compared with specific preventive intervention comprising low-dose risperidone therapy (mean dosage, 1.3 mg/d) and cognitive behavior therapy. Treatment was provided for 6 months, after which all patients were offered ongoing needs-based intervention. Assessments were performed at baseline, 6 months, and 12 months.

Results: By the end of treatment, 10 of 28 people who received needs-based intervention progressed to first-episode psychosis vs 3 of 31 from the specific preventive intervention group (P=.03). After 6-month follow-up, another 3 people in the specific preventive intervention group became psychotic, and with intention-to-treat analysis, the difference was no longer significant (P=.24). However, for risperidone therapy-adherent patients in the specific preventive intervention group, protection against progression extended for 6 months after cessation of risperidone use.

Conclusions: More specific pharmacotherapy and psychotherapy reduces the risk of early transition to psychosis in young people at ultra-high risk, although their relative contributions could not be determined. This represents at least delay in onset (prevalence reduction), and possibly some reduction in incidence.