Mechanisms of Sulforaphane Supplementation in Alleviating Negative Symptoms and Cognitive Impairment in Schizophrenia

Mechanisms of Sulforaphane Supplementation in Alleviating Negative Symptoms and Cognitive Impairment in Schizophrenia

The goal of this randomized, double-blind, placebo-controlled clinical trial with an open-label extension is to evaluate whether sulforaphane can improve negative symptoms and cognitive impairment, and to explore its underlying mechanisms in patients with schizophrenia (aged 12-45 years, both sexes, stable on antipsychotic medication). The study duration includes 12 weeks of double-blind treatment followed by a 12-week open-label extension. In the randomized controlled double-blind phase, a total of 60 participants will be randomized 1:1 to receive either six oral tablets (411 μmol GR) of sulforaphane (SFN group, n = 30) or placebo (placebo group, n = 30) for 12 weeks. In the open-label phase, participants will choose whether to continue taking the drugs originally assigned. The primary outcome is the change in PANSS and BNSS scores during the randomized double-blind phase. Secondary outcomes include changes in brain MRI measures, as well as changes in MCCB, CGI-SI, CGI-GI, PSP, SNS, and SAFTEE scores during the randomized double-blind phase; and changes in PANSS, BNSS, and MCCB scores during the open-label phase.SAFTEE scale, serious adverse event record and blood test will be used for safety monitoring.

Inclusion Criteria:

1. Diagnosis of schizophrenia according to DSM-5 criteria.
2. First-episode or illness duration ≤ 10 years, but currently in a non-acute phase of schizophrenia.
3. Negative symptoms present for ≥ 6 months prior to study entry. Patients must be outpatients or hospitalized for social reasons rather than symptom exacerbation.
4. PANSS negative subscale (7 items) total score ≥ 20; at least one negative item score > 3; no change > 3 points between screening and baseline. PANSS positive subscale items related to agitation (P4 excitement, P6 suspiciousness/persecution, P7 hostility, G8 uncooperativeness, G14 poor impulse control) each ≤ 4.
5. Currently taking ≤ 2 antipsychotic medications.
6. Antipsychotic regimen remains unchanged during the study period.
7. No anticipated relocation, transportation difficulties, or access problems that would interfere with study participation.
8. Able to understand and comply with study procedures, complete all required tests and examinations, communicate well with the investigator, and voluntarily provide written informed consent

Exclusion Criteria:

1. Psychiatric symptoms attributable to any other DSM-5 diagnosis besides schizophrenia.
2. History of substance dependence, or psychotic symptoms caused by other medical conditions.
3. Calgary Depression Scale for Schizophrenia (CDSS) total score > 6.
4. Barnes Akathisia Rating Scale (BARS) score indicating at least moderate akathisia.
5. Current or past major physical illness, neurological disorder, or traumatic brain injury affecting brain structure/function.
6. Suicidal attempt or current suicidal ideation.
7. Currently receiving antidepressants, mood stabilizers; or use of rTMS, MECT, or systematic psychotherapy within 3 months or for the current episode.
8. Current use of medications that may affect cognitive function, such as Ginkgo biloba extract, minocycline, selegiline.
9. Presence of hepatic or renal insufficiency, severe gastrointestinal, respiratory, endocrine, or hematologic disorders, or disorders of absorption or metabolism.
10. Pregnant or breastfeeding women.