Accelerated Neuromodulation Therapy and Neurocomputational Biomarkers in Individuals at Clinical High Risk for Psychosis

Overview

The goal of this study is to learn whether an accelerated form of neuromodulation therapy is safe, feasible, and well tolerated in young people at clinical high risk for psychosis (CHR-P), and whether it is associated with changes in candidate biomarkers of treatment response. Participants will be randomly assigned to receive either active accelerated intermittent theta burst stimulation (iTBS) or sham stimulation to the left dorsolateral prefrontal cortex, delivered over five consecutive days. The study will look at whether this accelerated treatment approach is safe and feasible for people at clinical high risk for psychosis, whether depressive symptoms improve after treatment, and whether computerized behavioural tasks and passive digital monitoring (wearables, smartphone apps, and speech analysis) can detect treatment-related changes that may serve as biomarkers for future, larger trials. Participants will complete clinical interviews and questionnaires, a cognitive battery, and computerized behavioral tasks; wear a Fitbit and use smartphone applications for at least two weeks before and throughout treatment; receive neuromodulation therapy or sham stimulation over five consecutive days; and attend follow-up visits at 1 week, 1 month, and 3 months after treatment.

There is currently no clinically validated treatment that reduces the risk of psychosis onset or mitigates the severity of a first psychotic episode in individuals at clinical high risk for psychosis (CHR-P). CHR-P is associated with attenuated psychotic symptoms, functional decline, and high rates of affective symptoms, including a comorbid mood disorder prevalence of 40% or higher. Repetitive transcranial magnetic stimulation (rTMS) targeting the left dorsolateral prefrontal cortex (LDLPFC) is an established treatment for depression and is increasingly supported for negative symptoms in psychotic disorders, making it a promising low-burden candidate for early intervention in CHR-P. This pilot study evaluates an accelerated intermittent theta burst stimulation (iTBS) protocol, delivered over five consecutive days, in individuals at CHR-P (SIPS-confirmed, aged 18-34). Forty participants will be randomized 1:1 to active accelerated iTBS or sham stimulation to the LDLPFC, using standard scalp-based (BEAM-F3) targeting rather than MRI-guided neuronavigation, reflecting the pilot nature and funding constraints of this early-phase study. Given the variable incidence of and long latency to psychosis onset in the CHR-P population, this study also incorporates a battery of neurocomputational tasks (analyzed using Hierarchical Gaussian Filter modeling) and a multimodal digital phenotyping framework (wearables, smartphone-based passive sensing, facial/vocal affect analysis, and structured speech analysis) to assess candidate biomarkers of treatment response. Primary outcomes are the safety, feasibility, and tolerability of the accelerated protocol in this population. Secondary outcomes include the sensitivity of neurocomputational biomarkers to treatment and change in depressive symptoms. Exploratory outcomes include treatment-related change across multiple domains of real-world functioning captured through digital phenotyping. This study is not designed to establish definitive treatment efficacy but to inform the design of future, adequately powered trials.