Farrell 2013.

Methods	Design: Randomised double‐blind placebo controlled pilot trial Study duration: 9 weeks Follow‐up: 3 months Country: Australia
Participants	Sample size: 17 children and adolescents were enrolled Recruitment: Children and adolescents with a primary diagnosis of OCD were enrolled at Griffith University between May 2009 and September 2010 Inclusion criteria ‐ diagnostic classification criteria: Primary diagnosis of OCD, child meeting criteria for "difficult‐to‐treat OCD", specific diagnostic criteria not reported Inclusion criteria ‐ rating scales: CY‐BOCS score of ≥ 19 Included disorders: OCD Co‐morbidities: 65% of the sample was presented with a secondary co‐morbid diagnosis and 53% presented with a tertiary diagnosis Diagnoses included: Specific phobia (3), GAD (8), MDD (2), SAnD (1), Social phobia (3), PTSD (1), ADD/ADHD (4) Gender: 41% male Mean age: mean age = 13.11 years (SD 3.33, range 8 to 18) Ethnicity: 94% Caucasian, 6% Asian Pharmacotherapy during the study: Naturalistic prescribing allowed. At study entry, 13 youth (76%) were on SRI medication and were stable on medication for at least 4 weeks, mean 51 weeks (range 4 to 240) and remained stable throughout the trial
Interventions	Intervention: Participants received 9 weekly 90 minute individual CBT sessions, including 5 sessions of ERP (sessions 5 to 9) combined with DCS. Participants received either 25 mg or 50 mg of DCS, depending on weight or participant (≤ 45 kg = 25 mg, > 45 kg = 50 mg) dispensed 1 hour prior to treatment sessions 5 to 9 (n = 9) Comparison: Participants received 9 weekly 90 minute individual CBT sessions, including 5 sessions of ERP (sessions 5 to 9) combined with placebo pill dispensed 1 hour prior to treatment sessions 5 to 9 (n = 8) Therapists: Therapists were all postgraduate‐level clinicians with previous experience in CBT for OCD. All clinicians received formal weekly supervision, wherein clinicians reported client progress, adherence to the treatment protocol, and provided and had an opportunity to ask questions and problem solve treatment difficulties or process issues
Outcomes	Responders; withdrawals; remission; anxiety: CY‐BOCS; co‐morbid anxiety: MASC; adverse events
Notes	Funding from industry: No, this trial was supported by an Australian Rotary Health Research Fund grant Medication supplied by industry: Not reported Any author work for industry: Not reported Study ID: ACTRN12609000370202
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Children were randomised using a computer‐generated list of randomly permuted blocks of pairs, with an allocation of 1:1 to either ERP + DCS or ERP + PBO"
Allocation concealment (selection bias)	Unclear risk	Details not provided
Blinding of participants and personnel (performance bias) All outcomes	Low risk	"All other investigators were blind, as were assessors, therapists, and all participants." "Pills were compounded to be identical in size and colour, and were dispensed by the study pharmacist corresponding to randomisation"
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Therapists and assessors were blinded. Additionally, some outcome assessments were self‐reports
Incomplete outcome data (attrition bias) All outcomes	Low risk	"All children enrolled in the trial completed treatment"
Selective reporting (reporting bias)	Low risk	All outcomes stated in the protocol were reported
Other bias	Unclear risk	Greater than 75% of patients (13/17 patients) were receiving concomitant medications, which might have confounded the results