Storch 2007.

Methods	Design: Randomised, double‐blind, placebo controlled trial Study duration: 12 weeks Follow‐up: 2 months Country: USA
Participants	Sample size: 24 participants eligible and agreed to participate Recruitment: Participants were recruited from patients who presented at the University of Florida OCD Program for treatment Inclusion criteria ‐ diagnostic classification criteria: primary diagnosis of OCD, DSM‐IV‐TR Inclusion criteria ‐ rating scales: Yale‐Brown Obsessive Compulsive Scale (YBOC‐S) Included disorders: OCD Co‐morbidities: GAD 50%, MDD 25%, dysthymia 16%, social phobia 25%, panic disorder 21%, tricotillomania 4% Gender: 50% male Mean age: 29.9 years (SD 9.9 years) Ethnicity: 92% White, 4% African American, 4% Asian Pharmacotherapy during the study: 50% of participants were taking SSRIs
Interventions	Intervention: Participants received 250 mg doses of DCS administered 4 hours prior to each weekly session of ERP therapy, total 12 sessions (n = 12) Comparison: Participants received placebo pill administered 4 hours prior to each weekly session of ERP therapy, total 12 sessions (n = 12) Therapists: Therapy was conducted by the first author or doctoral fellows or trainees under his supervision
Outcomes	Response; withdrawals; remission; anxiety: Y‐BOCS; co‐morbid depression: BDI‐II; adverse events
Notes	Funding from Industry: This work was supported by a grant to the first author from the Obsessive–Compulsive Foundation Medication supplied by industry: Unclear, Seromycin, Eli Lilly, USA Authors work for industry: Unsure Study ID: Not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	'Participants were randomised to receive DCS or placebo.' Sequence generation not stated. Marked as low risk, as other included publications by author used computer generated random number generation (Storch 2010) therefore likely to be similar
Allocation concealment (selection bias)	Low risk	'The rater, the treatment teams, the patients and their families were unaware of and unable to determine, the study drug assignment by appearance or otherwise'
Blinding of participants and personnel (performance bias) All outcomes	Low risk	'The rater, the treatment teams, the patients and their families were unaware of and unable to determine, the study drug assignment by appearance or otherwise'
Blinding of outcome assessment (detection bias) All outcomes	Low risk	'The rater, the treatment teams, the patients and their families were unaware of and unable to determine, the study drug assignment by appearance or otherwise'
Incomplete outcome data (attrition bias) All outcomes	Low risk	Missing data balanced in numbers across intervention groups with similar reasons for missing data across groups.' Thirty‐four participants randomised with n = 17 across each arm; n = 12 received allocation in each arm as n = 5 for each arm withdrew. Exactly the same number and reasons sited across both groups; n = 3 for each group refusing to sign consent form, n = 1 for each group withdrawing before the second session, n = 1 for each arm withdrawing as unwilling to receive cognitive and behavioural therapies; n = 1 for each arm lost to follow‐up as unable to be contacted
Selective reporting (reporting bias)	Unclear risk	Study protocol not available thus unsure if all of study's pre‐specified outcomes of interest reported in pre‐specified way
Other bias	Unclear risk	A total of 50% of patients were receiving concomitant anti‐depressants, which might have confounded the results