Parker 2019.

Study characteristics
Methods	4‐week trial of vasopressin versus placebo
Participants	Inclusion criteria: met diagnostic criteria for ASD medically healthy outpatients aged 6‐12.9 years IQ ≥ 50 as determined by the Stanford Binet 5th Edition CGI‐S scale rating of ≥ 4 care provider who can reliably bring participant to clinic visits, provides trustworthy ratings, and interacts with the participant on a regular basis stable concomitant medications for at least 4 weeks no planned changes in psychosocial interventions during the trial willing and able to provide blood samples and undergo ECGs Exclusion criteria: previous or current use of vasopressin abnormal chemistry result ECG abnormality as determined by the study pediatric cardiologist DSM‐IV‐TR diagnosis of schizophrenia, schizoaffective disorder, or psychotic disorder regular nasal obstruction or nosebleeds active medical problems: uncontrolled seizures and physical illness (e.g. serious liver, renal, or cardiac pathology) sensitivity to preservatives (e.g. chlorobutanol) evidence of a genetic mutation known to cause ASD (e.g., fragile X syndrome) hearing or vision impairments habitually drinks large volumes of water pregnant, breastfeeding, or childbirth within the last 6 months sexually active girls not using a reliable method of contraception; negative urine pregnancy test required for girls who'd started menstruating. Location/setting: autism disorders clinic, USA Sample size: 30 Number of withdrawals/dropouts: none reported Gender: 25 male, 5 female Mean age: 6‐12.9 years of age (outpatients) IQ: approximately 77‐98 Baseline ABC‐I or other BoC: baseline ABC‐I 8.29 (7.4); baseline QoL 64.53 (13.86) Concomitant medications: details not provided History of previous medications: details not provided
Interventions	Intervention (vasopressin nasal spray): 4 IU twice daily of vasopressin during week 1 and 8 IU twice daily of vasopressin during week 2. Participants aged 6‐9.5 years then received 12 IU twice daily of vasopressin during weeks 3 and 4, whereas participants aged 9.6‐12.9 years received 16 IU twice daily of vasopressin during weeks 3 and 4. Comparator (placebo nasal spray): matching placebo for 4 weeks
Outcomes	Primary outcomes: ABC‐I (Aman 1985) AEs Secondary outcomes: QoL, measured with parent‐rated PedsQL (WHO 1998) tolerability Timing of outcome assessments: ABC‐I and QoL were measured at baseline and week 4 (endpoint). Participants underwent weekly safety/tolerability assessments in the clinic to monitor for AEs.
Notes	Study start date: December 2013 Study end date: May 2017 Funding: various grants to the researchers Conflicts of interest: financial compensation by pharmaceutical companies and other involvement with pharmaceutical companies Trial registry: NCT01962870
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation was performed by an unblinded investigator using a machine‐generated treatment schedule, which allocated each participant to an intervention.
Allocation concealment (selection bias)	Unclear risk	Details not provided
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Research team, parents/legal guardians, and child participants remained blind throughout the trial's duration.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Research team, parents/legal guardians, and child participants remained blind throughout the trial's duration.
Incomplete outcome data (attrition bias) All outcomes	Low risk	There were no dropouts reported and all were included in the analysis.
Selective reporting (reporting bias)	High risk	PedsQL and ABC not reported in peer‐reviewed paper. The Overt Aggression Scale was mentioned as an outcome but not reported.
Other bias	Low risk	No other sources identified