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.

Study Overview

• Status: Not yet recruiting
• Conditions: Schizophrenia Disorder
• Intervention / Treatment: Dietary supplement: Placebo; Dietary supplement: Sulforaphane

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Jing Huang, Prof.; Phone Number: +8613107212438; Email: jinghuangserena@csu.edu.cn

Study Locations

• China
  • Changsha, China, 410001
    • Xiangya Second Hospital
    • Contact: Jing Huang; Phone Number: +8613107212438; Email: jinghuangserena@csu.edu.cn

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: No

Description

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. Hepatic or renal impairment: aspartate aminotransferase (AST), alanine aminotransferase (ALT), or gamma-glutamyl transferase (GGT) > 2× upper limit of normal (ULN); and/or creatinine > 1.2× ULN or > 2 mg/dL; or any other evidence of significant liver/kidney damage as judged by the investigator.
10. Presence of hepatic or renal insufficiency, severe gastrointestinal, respiratory, endocrine, or hematologic disorders, or disorders of absorption or metabolism.
11. Any laboratory value significantly outside the reference range and clinically significant as judged by the investigator.
12. Pregnant or breastfeeding women.
13. Any other condition that, in the investigator's opinion, makes the patient unsuitable for participation in this trial.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo	Dietary supplement: Placebo; Participants take 6 tablets of matching placebo daily for the first 3 months (randomized double-blind phase). During the subsequent 3-month open-label extension phase, those who choose to continue their original assigned medication also take 6 tablets of matching placebo per day, i.e., six placebo tablets daily. Both active and placebo tablets are manufactured uniformly by Shenzhen Fushan Biotech Co., Ltd. (China), with identical appearance and similar smell and taste.
Experimental: sulforaphane	Dietary supplement: Sulforaphane; Participants take 6 tablets of sulforaphane daily for the first 3 months (randomized double-blind phase). During the subsequent 3-month open-label extension phase, those who choose to continue their original assigned medication also take 6 tablets of sulforaphane per day, equivalent to a dosage of six active tablets (411 μmol GR). The sulforaphane-producing dietary supplement, ZHIYINGUOSU, is provided at no cost by Shenzhen Fushan Biotech Co., Ltd. (China).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from baseline in the Positive and Negative Syndrome Scale (PANSS) negative subscale score	PANSS negative subscale assesses severity of negative symptoms (score range 7-49, higher = worse). Change scores are calculated as the score at each time point (6 and 12 weeks) minus the baseline score. A negative change at either time point indicates improvement.	Baseline to 6 and 12 weeks
Change from baseline in Brief Negative Symptom Scale (BNSS) score	The BNSS measures negative symptom severity (total score 0-78, higher = worse). Change from baseline = score at week minus baseline score (calculated separately for week 6 and week 12). A negative change at either time point indicates improvement.	Baseline to 6 and 12 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from baseline in MATRICS Consensus Cognitive Battery (MCCB) score	The MCCB assesses seven cognitive domains. Positive change indicates cognitive improvement.	Baseline to 12 weeks
Brain imaging changes	Evaluation of brain imaging changes from baseline at week 12. The scanning protocol includes structural imaging, functional imaging, diffusion imaging, myelin imaging, and magnetic resonance spectroscopy imaging, to systematically evaluate brain structure, functional connectivity, white matter microstructure, myelin integrity, and neurometabolic profiles in patients with schizophrenia.	Baseline to 12 weeks
Change in serum biomarker levels	Evaluation of peripheral blood biomarkers of inflammation, oxidative stress and metabolism	Baseline to 12 weeks
Change in PANSS negative subscale score (open-label extension)	Evaluation of the change from week 12 in the negative symptom subscale of PANSS at week 24. Change = score at 24 weeks minus score at week 12. Negative change indicates further improvement during extension.	Week 12 to 24
Change in Brief Negative Symptom Scale (BNSS) (open-label extension)	BNSS total score (0-78, higher=worse). Change = 24-week score minus week-12 score. Negative change indicates further improvement during extension.	Week 12 to 24
Change in the composite score of MATRICS Consensus Cognitive Battery (MCCB) (open-label extension)	Evaluation of the score and change from week 12 in MCCB composite score at week 24. Change = 24-week score minus week-12 score. Positive change indicates further improvement during extension	Week 12 to 24
Change in serum biomarker levels (open-label extension)	Serum biomarker concentrations. Change = level at 24 weeks minus level at week 12.	Week 12 to 24
Clinical Global Impression - Severity of Illness (CGI-SI) score	CGI-SI rates illness severity on a 7-point scale (1=normal, 7=extremely ill). Change = score at week minus baseline score (separately for week 6 and week 12). Negative change indicates improvement.	Baseline to 6 and 12 weeks
Clinical Global Impression - Global Improvement (CGI-GI) score	The CGI-GI rates overall change on a 7-point scale (1=very much improved, 4=no change, 7=very much worse). The score at each time point (6 and 12 weeks) directly reflects improvement since baseline; lower scores mean greater improvement.	Week 6 and week 12
Change in Self-rating Negative Symptom Scale (SNS) score	The SNS is a self-reported scale completed by the patient to assess the severity of negative symptoms. Each item is scored on a 3-point scale (0=strongly disagree, 1=slightly agree, 2=completely agree), yielding a total score ranging from 0 to 40, with higher scores indicating more severe negative symptoms. Change scores are calculated as the score at each time point (6 and 12 weeks) minus the baseline score. A negative change at either time point indicates symptomatic improvement.	Baseline to 6 and 12 weeks
Change in Personal and Social Performance (PSP) total score	The PSP total score ranges 1-100 (higher = better personal and social functioning). Change = week score minus baseline score (separately for week 6 and week 12). Positive change means functional improvement.	Baseline to 6 and 12 weeks
Change in Barnes Akathisia Rating Scale (BARS) total score	The BARS measures akathisia severity (total score 0-14, higher = worse). Change = week score minus baseline score (separately for week 6 and week 12). Negative change indicates reduced akathisia.	Baseline to 6 and 12 weeks
Change in Systematic Assessment for Treatment Emergent Events (SAFTEE) total score	The SAFTEE total score reflects adverse event burden (higher score = greater burden). Change = week score minus baseline score (separately for week 6 and week 12). Negative change means reduction in adverse events.	Baseline to 6 and 12 weeks
Clinical Global Impression - Severity of Illness (CGI-SI) score (open-label extension)	CGI-SI rates illness severity on a 7-point scale (1=normal, 7=extremely ill).	Week 24
Clinical Global Impression - Global Improvement (CGI-GI) score (open-label extension)	The CGI-GI rates overall change on a 7-point scale (1=very much improved, 4=no change, 7=very much worse). The score at 24 weeks directly reflects improvement since baseline; lower scores mean greater improvement.	Week 24
Change in Self-rating Negative Symptom Scale (SNS) score (open-label extension)	The SNS is a patient-reported outcome measuring negative symptom severity using a 3-point scale per item (0=strongly disagree, 1=slightly agree, 2=completely agree), with a total score range of 0 to 40 (higher = worse). Change is calculated as the score at 24 weeks minus the score at week 12. A negative change indicates further improvement in negative symptoms during the extension phase.	Week 12 to 24
Change in Personal and Social Performance (PSP) total score (open-label extension)	The PSP total score ranges 1-100 (higher = better personal and social functioning). Change = week 24 score minus week 12 score. Positive change means functional improvement.	Week 12 to 24
Change in BARS total score (open-label extension)	The BARS measures akathisia severity (total score 0-14, higher = worse). Change = week score minus baseline score (separately for week 6 and week 12). Negative change indicates reduced akathisia.	Week 12 to 24
Change in Systematic Assessment for Treatment Emergent Events (SAFTEE) total score (open-label extension)	he SAFTEE total score reflects adverse event burden (higher score = greater burden). Change = week 24 score minus week 12 score. Negative change means reduction in adverse events.	Week 12 to 24

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Complete Blood Count (CBC)	Evaluation of red blood cell count, white blood cell count, platelet count, hemoglobin, neutrophil percentage, lymphocyte percentage, and monocyte percentage, as well as change from baseline at week 12 and week 24.	Baseline, week 12 and week 24
Blood Biochemistry	Evaluation of liver function (ALT, AST, ALP, total bilirubin, direct bilirubin, total protein, albumin), as well as change from baseline at week 12 and week 24.	Baseline, week 12 and week 24
Biochemistry of renal function (creatinine, urea)	Evaluation of renal function (creatinine, urea), as well as change from baseline at week 12 and week 24.	Baseline, week 12 and week 24

Collaborators and Investigators

• Sponsor: Second Xiangya Hospital of Central South University

Study record dates

Study Major Dates

• Study Start (Estimated): June 2, 2026
• Primary Completion (Estimated): December 31, 2028
• Study Completion (Estimated): December 31, 2028

Study Registration Dates

• First Submitted: June 9, 2026
• First Submitted That Met QC Criteria: June 16, 2026
• First Posted (Actual): June 17, 2026

Study Record Updates

• Last Update Posted (Actual): June 17, 2026
• Last Update Submitted That Met QC Criteria: June 16, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Schizophrenia Spectrum and Other Psychotic Disorders; Mental Disorders; Schizophrenia; sulforaphane
• Other Study ID Numbers: LYG20210114

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No