Le 2022.

Study characteristics
Methods	6 week cross‐over trial of oxytocin versus placebo
Participants	Inclusion criteria: aged 3‐8 years meet the DSM‐5 criteria for ASD diagnosis meet the ADOS‐2 criteria for ASD not in receipt of any psychotropics in the previous 3 months parent or participant consent to participate Exclusion criteria: previous or current use of oxytocin meet the DSM‐5 criteria for any mental disorders "ASD accompanied with severe behavioural disorders" any serious medical conditions, including neurological, endocrine, cardiovascular, or gastrointestinal disorders any chronic nasal disorders that impact the ability to use nasal sprays hearing or vision impairments allergic to oxytocin Location/setting: China Sample size: 41 (21 oxytocin, 20 placebo) Number of withdrawals/dropouts: none were lost to follow‐up in the first phase of the cross‐over trial Gender: male (38), female (3) Mean age: 5.0 years across both groups IQ: not reported Baseline ABC‐I or other BoC scores: not an outcome Concurrent medications: details not provided History of previous medications: details not provided
Interventions	Intervention (oxytocin) followed by placebo: oxytocin nasal spray 24 IU every 2nd day for 6 weeks, followed by a 2‐week wash‐out period before starting the 2nd phase of the cross‐over trial Comparator (placebo) followed by oxytocin: equivalent placebo (24 IU) every 2nd day for 6 weeks, followed by a 2‐week wash‐out period before starting the 2nd phase of the cross‐over trial
Outcomes	Primary outcomes: AEs Secondary outcomes: not reported Timing of outcome assessments: unclear
Notes	Source of funding: University of Electronic Science and Technology of China, UESTC high‐level research fostering project Conflicts of interest: "The authors have no conflicts of interest to declare"
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	1:1 computer‐generated randomisation
Allocation concealment (selection bias)	Unclear risk	Intranasal spay bottles for oxytocin or placebo were identical in appearance and labelling with each having a unique code.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Intranasal spray bottles were labelled and distributed to carers by an individual not involved in any other aspect of the trial who was responsible for finally unmasking the treatment details at the end of the trial.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Intranasal spray bottles were labelled and distributed to carers by an individual not involved in any other aspect of the trial who was responsible for finally unmasking the treatment details at the end of the trial.
Incomplete outcome data (attrition bias) All outcomes	Low risk	1 of 21 LTFU in oxytocin group and 1 in 22 in placebo group
Selective reporting (reporting bias)	Unclear risk	There were no serious AEs in either group but the only other AE that was reported was urination frequency.
Other bias	Low risk	No differences in age, gender, baseline scores of autism subtype