Long-term follow-up of a group at ultra high risk ("prodromal") for psychosis: the PACE 400 study

Abstract

Importance: The ultra high-risk (UHR) criteria were introduced to prospectively identify patients at high risk of psychotic disorder. Although the short-term outcome of UHR patients has been well researched, the long-term outcome is not known.

Objective: To assess the rate and baseline predictors of transition to psychotic disorder in UHR patients up to 15 years after study entry.

Design: Follow-up study of a cohort of UHR patients recruited to participate in research studies between 1993 and 2006.

Setting: The Personal Assessment and Crisis Evaluation (PACE) clinic, a specialized service for UHR patients in Melbourne, Australia.

Participants: Four hundred sixteen UHR patients previously seen at the PACE clinic.

Main outcomes and measures: Transition to psychotic disorder, as measured using the Comprehensive Assessment of At-Risk Mental States, Brief Psychiatric Rating Scale/Comprehensive Assessment of Symptoms and History, or state public mental health records.

Results: During the time to follow-up (2.4-14.9 years after presentation), 114 of the 416 participants were known to have developed a psychotic disorder. The highest risk for transition was within the first 2 years of entry into the service, but individuals continued to be at risk up to 10 years after initial referral. The overall rate of transition was estimated to be 34.9% over a 10-year period (95% CI, 28.7%-40.6%). Factors associated with transition included year of entry into the clinic, duration of symptoms before clinic entry, baseline functioning, negative symptoms, and disorders of thought content.

Conclusions and relevance: The UHR patients are at long-term risk for psychotic disorder, with the highest risk in the first 2 years. Services should aim to follow up patients for at least this period, with the possibility to return for care after this time. Individuals with a long duration of symptoms and poor functioning at the time of referral may need closer monitoring. Interventions to improve functioning and detect help-seeking UHR patients earlier also may be indicated.