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NCT Number: NCT07652866

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.

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Key information

Conditions

Schizophrenia Disorder Mental Disorders Schizophrenia Schizophrenia Spectrum and Other Psychotic Disorders

Age range

12 year–45 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Diagnosis of schizophrenia according to DSM-5 criteria.
  • First-episode or illness duration ≤ 10 years, but currently in a non-acute phase of schizophrenia.
  • Negative symptoms present for ≥ 6 months prior to study entry. Patients must be outpatients or hospitalized for social reasons rather than symptom exacerbation.
  • 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.
  • Currently taking ≤ 2 antipsychotic medications.
  • Antipsychotic regimen remains unchanged during the study period.
  • No anticipated relocation, transportation difficulties, or access problems that would interfere with study participation.
  • 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

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

Treatment and study plan

Placebo

Dietary Supplement

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.

Sulforaphane

Dietary Supplement

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).

Primary outcomes

  1. Change from baseline in the Positive and Negative Syndrome Scale (PANSS) negative subscale score

    Time frame: Baseline to 6 and 12 weeks

    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.

  2. Change from baseline in Brief Negative Symptom Scale (BNSS) score

    Time frame: Baseline to 6 and 12 weeks

    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.

Secondary outcomes

  1. Change from baseline in MATRICS Consensus Cognitive Battery (MCCB) score

    Time frame: Baseline to 12 weeks

    The MCCB assesses seven cognitive domains. Positive change indicates cognitive improvement.

  2. Brain imaging changes

    Time frame: Baseline to 12 weeks

    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.

  3. Change in serum biomarker levels

    Time frame: Baseline to 12 weeks

    Evaluation of peripheral blood biomarkers of inflammation, oxidative stress and metabolism

  4. Change in PANSS negative subscale score (open-label extension)

    Time frame: Week 12 to 24

    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.

  5. Change in Brief Negative Symptom Scale (BNSS) (open-label extension)

    Time frame: Week 12 to 24

    BNSS total score (0-78, higher=worse). Change = 24-week score minus week-12 score. Negative change indicates further improvement during extension.

  6. Change in the composite score of MATRICS Consensus Cognitive Battery (MCCB) (open-label extension)

    Time frame: Week 12 to 24

    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

  7. Change in serum biomarker levels (open-label extension)

    Time frame: Week 12 to 24

    Serum biomarker concentrations. Change = level at 24 weeks minus level at week 12.

  8. Clinical Global Impression - Severity of Illness (CGI-SI) score

    Time frame: Baseline to 6 and 12 weeks

    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.

  9. Clinical Global Impression - Global Improvement (CGI-GI) score

    Time frame: Week 6 and week 12

    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.

  10. Change in Self-rating Negative Symptom Scale (SNS) score

    Time frame: Baseline to 6 and 12 weeks

    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.

  11. Change in Personal and Social Performance (PSP) total score

    Time frame: Baseline to 6 and 12 weeks

    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.

  12. Change in Barnes Akathisia Rating Scale (BARS) total score

    Time frame: Baseline to 6 and 12 weeks

    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.

  13. Change in Systematic Assessment for Treatment Emergent Events (SAFTEE) total score

    Time frame: Baseline to 6 and 12 weeks

    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.

  14. Clinical Global Impression - Severity of Illness (CGI-SI) score (open-label extension)

    Time frame: Week 24

    CGI-SI rates illness severity on a 7-point scale (1=normal, 7=extremely ill).

  15. Clinical Global Impression - Global Improvement (CGI-GI) score (open-label extension)

    Time frame: Week 24

    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.

  16. Change in Self-rating Negative Symptom Scale (SNS) score (open-label extension)

    Time frame: Week 12 to 24

    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.

  17. Change in Personal and Social Performance (PSP) total score (open-label extension)

    Time frame: Week 12 to 24

    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.

  18. Change in BARS total score (open-label extension)

    Time frame: Week 12 to 24

    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.

  19. Change in Systematic Assessment for Treatment Emergent Events (SAFTEE) total score (open-label extension)

    Time frame: Week 12 to 24

    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.

Other outcomes

  1. Complete Blood Count (CBC)

    Time frame: Baseline, week 12 and week 24

    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.

  2. Blood Biochemistry

    Time frame: Baseline, week 12 and week 24

    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.

  3. Biochemistry of renal function (creatinine, urea)

    Time frame: Baseline, week 12 and week 24

    Evaluation of renal function (creatinine, urea), as well as change from baseline at week 12 and week 24.

Study contacts

Contact information is provided by the study sponsor or research team.

Jing Huang, Prof.

CONTACT

[email protected]

+8613107212438

Sponsors and collaborators

Lead sponsor

Second Xiangya Hospital of Central South University

Other

Registry information

Important dates

Study start
2026
Primary completion
2028
Study completion
2028
First posted
Jun 17, 2026
Registry last updated
Jun 18, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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