Table 1.

Characteristics and findings of reviewed clinical studies

Disorder and first author (year)	Study design, participant age and group	SFN treatment (route/dose)	Study duration	Main findings
ASD, Singh (2014)47	RCT, 13–27 years. SFN (n=26), placebo (n=14).	Oral route. Weight-based dose: 50 µmol (<45.36 kg), 100 µmol (45.81–90.26 kg) or 150 µmol (>90.72 kg) per day.	22 weeks (18 weeks of treatment; 4 weeks of follow-up without treatment).	SFN significantly improved ABC and SRS scores by 34% (p<0.001) and 17% (p=0.017), respectively, as well as improved the social interaction (p=0.007), abnormal behaviour (p=0.014) and verbal communication (p=0.015) on CGI-I. When the administration of sulforaphane stopped, the total scores of all scales returned to pretreatment levels.
ASD, Bent (2018)49	Open-label study, 5–22 years. SFN (n=15).	Oral route. Weight-based dose: 1.14 µmol/kg.	12 weeks.	SFN significantly improved the ABC score by 7.1 points (-7.1) (95% CI: −17.4 to 3.2, p=0.18) and SRS score by 9.7 points (-9.7) (95% CI: −18.7 to −0.8, p=0.03).
ASD, Momtazmanesh (2020)50	RCT, 4–12 years. Risperidone+SFN (n=30), risperidone+placebo (n=30).	Oral route. Weight-based dose: 50 µmol (≤45 kg) or 100 µmol (>45 kg) per day.	10 weeks.	SFN showed significant improvement in irritability score (p=0.001) and hyperactivity/non-compliance score (p=0.015), as well as significant time by treatment effect for irritability (p=0.007) and hyperactivity/non-compliance (p=0.008).
ASD, Zimmerman (2021)29	RCT, 3–12 years. SFN (n=22), placebo (n=23).	Oral route. Weight-based dose: 2.2 µmol/kg/day.	36 weeks (15 weeks of treatment; open-label SFN treatment of all children for 15 weeks; 6 weeks of follow-up without treatment).	SFN showed significant improvement on the ABC scale at 15 weeks (p<0.02) and a tendency to improve the total score on OACIS-I at 7 and 15 weeks.
Depression, Ghazizadeh-Hashemi (2021)51	RCT, 40–65 years+cardiac intervention history. SFN (n=30), placebo (n=30).	Oral route 30 mg/day.	6 weeks.	The sulforaphane group exhibited greater improvement on HAM-D scores (p<0.001), higher rate of response to treatment (30% vs 6.67%, p=0.042) and an upward tendency towards remission (23.33% vs 3.33%, p=0.052).
Schizophrenia, Shiina (2015)54	Open-label study, 20–65 years. SFN (n=7).	Oral route 30 mg/day.	8 weeks.	After SFN treatment, the mean scores in the OCLT showed a significant increase from 0.88 to 0.95 (p=0.043).
Schizophrenia, Dickerson (2021)55	RCT, 18–65 years. SFN (n=29), placebo (n=29).	100 µmol/day.	18 weeks (2 weeks of single-blind placebo treatment followed by 16 weeks of double-blind SFN or placebo treatment).	No significant difference in psychiatric symptoms or cognitive function was observed between the SFN or placebo group.

ABC, Aberrant Behavior Checklist; ASD, autism spectrum disorder; CGI-I, Clinical Global Impression Improvement Scale; HAM-D, Hamilton Rating Scale for Depression; OACIS-I, Ohio Autism Clinical Impressions Scale-Improvement; OCLT, One Card Learning Task; RCT, randomised clinical trials; SFN, sulforaphane; SRS, Social Responsiveness Scale.