Importance

Clinical trials have not established the optimal type, sequence, and duration of interventions for people at ultrahigh risk of psychosis.

Objective

To determine the effectiveness of a sequential and adaptive intervention strategy for individuals at ultrahigh risk of psychosis.

Design, setting, and participants

The Staged Treatment in Early Psychosis (STEP) sequential multiple assignment randomized trial took place within the clinical program at Orygen, Melbourne, Australia. Individuals aged 12 to 25 years who were seeking treatment and met criteria for ultrahigh risk of psychosis according to the Comprehensive Assessment of At-Risk Mental States were recruited between April 2016 and January 2019. Of 1343 individuals considered, 342 were recruited.

Interventions

Step 1: 6 weeks of support and problem solving (SPS); step 2: 20 weeks of cognitive-behavioral case management (CBCM) vs SPS; and step 3: 26 weeks of CBCM with fluoxetine vs CBCM with placebo with an embedded fast-fail option of ω-3 fatty acids or low-dose antipsychotic medication. Individuals who did not remit progressed through these steps; those who remitted received SPS or monitoring for up to 12 months.

Main outcomes and measures

Global Functioning: Social and Role scales (primary outcome), Brief Psychiatric Rating Scale, Scale for the Assessment of Negative Symptoms, Montgomery-Åsberg Depression Rating Scale, quality of life, transition to psychosis, and remission and relapse rates.

Results

The sample comprised 342 participants (198 female; mean [SD] age, 17.7 [3.1] years). Remission rates, reflecting sustained symptomatic and functional improvement, were 8.5%, 10.3%, and 11.4% at steps 1, 2, and 3, respectively. A total of 27.2% met remission criteria at any step. Relapse rates among those who remitted did not significantly differ between SPS and monitoring (step 1: 65.1% vs 58.3%; step 2: 37.7% vs 47.5%). There was no significant difference in functioning, symptoms, and transition rates between SPS and CBCM and between CBCM with fluoxetine and CBCM with placebo. Twelve-month transition rates to psychosis were 13.5% (entire sample), 3.3% (those who ever remitted), and 17.4% (those with no remission).

Conclusions and relevance

In this sequential multiple assignment randomized trial, transition rates to psychosis were moderate, and remission rates were lower than expected, partly reflecting the ambitious criteria set and challenges with real-world treatment fidelity and adherence. While all groups showed mild to moderate functional and symptomatic improvement, this was typically short of remission. While further adaptive trials that address these challenges are needed, findings confirm substantial and sustained morbidity and reveal relatively poor responsiveness to existing treatments.

Trial registration

ClinicalTrials.gov Identifier: NCT02751632.

This article describes the rationale, aims, and methodology of the Accelerating Medicines Partnership® Schizophrenia (AMP® SCZ). This is the largest international collaboration to date that will develop algorithms to predict trajectories and outcomes of individuals at clinical high risk (CHR) for psychosis and to advance the development and use of novel pharmacological interventions for CHR individuals. We present a description of the participating research networks and the data processing analysis and coordination center, their processes for data harmonization across 43 sites from 13 participating countries (recruitment across North America, Australia, Europe, Asia, and South America), data flow and quality assessment processes, data analyses, and the transfer of data to the National Institute of Mental Health (NIMH) Data Archive (NDA) for use by the research community. In an expected sample of approximately 2000 CHR individuals and 640 matched healthy controls, AMP SCZ will collect clinical, environmental, and cognitive data along with multimodal biomarkers, including neuroimaging, electrophysiology, fluid biospecimens, speech and facial expression samples, novel measures derived from digital health technologies including smartphone-based daily surveys, and passive sensing as well as actigraphy. The study will investigate a range of clinical outcomes over a 2-year period, including transition to psychosis, remission or persistence of CHR status, attenuated positive symptoms, persistent negative symptoms, mood and anxiety symptoms, and psychosocial functioning. The global reach of AMP SCZ and its harmonized innovative methods promise to catalyze the development of new treatments to address critical unmet clinical and public health needs in CHR individuals.