Decreasing risk of psychosis by sulforaphane study protocol for a randomized, double-blind, placebo-controlled,...

A growing number of studies suggest a role of neuroinflammation and oxidative stress in the pathophysiology of psychosis. Sulforaphane (SFN), a natural compound extracted from cruciferous vegetables, has shown anti-inflammatory and anti-oxidative effects which imply a potential effect on decreasing the risk of psychosis. However, there is no study testing the efficacy of SFN for this purpose. It's necessary to evaluate its efficacy on individuals at clinical high risk (CHR) for psychosis.

This is a randomized, double-blind, placebo-controlled, multi-centre trial. A total of 300 CHR subjects will be identified in the course of face-to-face interviews using the Structured Interview for Prodromal Syndromes. All participants will be randomly allocated to SFN group (n = 150) or placebo group (n = 150). The study duration includes an intervention for 52 consecutive weeks, and additional 1-year follow-up.

The primary outcome is 2-year conversion rate of psychosis. Secondary outcomes include 1-year conversion rate of psychosis, the severity and duration of prodromal symptoms, predictive risk of psychosis conversion, neurocognitive functioning and peripheral blood biomarkers of inflammation, oxidative stress and metabolism. Safety monitoring will be performed using scales for side effect, serious adverse events recording, and laboratory tests.

This trial is expected to clarify the efficacy of SFN in improving prodromal symptoms, and its role in decreasing the risk and conversion rate of psychosis among CHR subjects. The results will also provide solid evidence about the efficacy and safety of SFN in CHR population. Potential challenges and their solutions in performing the present trial are discussed.