King 2009.

Study characteristics
Methods	Parallel trial of citalopram versus placebo
Participants	Inclusion criteria: meet the DSM‐4‐TR criteria for ASD, Asperger's disorder, or PDD have an illness severity rating of at least moderate on the CGI‐S score at least moderate on compulsive behaviours Exclusion criteria: details not provided Location/setting: s6 academic medical centres in the USA Sample size: 149 (73 children were randomised to citalopram and 76 to placebo) Number of withdrawals/dropouts: placebo: 13 withdrew (7 AEs, 1 protocol violation, 5 withdrew consent) Citalopram hydrobromide: 13 withdrew (1 serious AE, 8 AEs, 2 protocol violations, 2 withdrew consent) Mean age: 9.4 years Gender: 128/149 boys IQ: 43% had nonverbal IQ > 70 Baseline ABC‐I or other BoC: citalopram ABC‐I 13.2; placebo 11.2; self‐injurious behaviour 2.8 (citalopram); 2.6 (placebo) Concomitant medications: psychotropic medication not allowed during the study. Only sleep medications allowed History of previous medications: details not provided
Interventions	Intervention (citalopram hydrobromide) for 12 weeks: 10 mg/5 mL. Mean maximum dose was 16.5 mg/day (± 6.5 mg) Comparator (placebo) for 12 weeks: equivalent placebo
Outcomes	Primary outcomes: Irritability, measured using the ABC‐Irritability subscale (Aman 1985) self‐injurious behaviour, measured using the Repetitive Behavior Scale‐Self‐Injurious subscale (Bodfish 2000) Secondary outcomes: none reported Timing of outcome assessments: AEs assessed at bi‐weekly visits; ABC‐I and self‐injury measured at baseline and endpoint
Notes	Study start date: April 2004 Study end date: October 2006 Source of funding: all authors received salary contributions from the National Institutes of Health, which supported this study. Conflicts of interest: none declared
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Participants were randomly assigned to citalopram or placebo using permuted blocks with randomly varying block sizes stratified by site and by age (5‐11 vs 12‐17 years)
Allocation concealment (selection bias)	Unclear risk	Details not provided
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Two masked clinicians met with participants during each scheduled evaluation
Blinding of outcome assessment (detection bias) All outcomes	Low risk	The evaluating clinician monitored efficacy and was blinded to AEs
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	LTFU citalopram: 13 withdrew, 1 due to serious AE; 8 AEs; 2 protocol violations; 2 consent withdrawn LTFU placebo: 13 withdrawn, 7 AEs; 1 protocol violation; 5 consent withdrawn
Selective reporting (reporting bias)	Low risk	The trial protocol was recorded on Clinicaltrials.gov and outcomes were reported in the paper.
Other bias	High risk	Study authors all work with/for pharmaceutical companies