Nave 2012.

Methods	Design: double‐blind, randomised pilot study Study duration: 1 week (1 session, plus assessment 1 week before) Follow‐up: 1 week Country: USA
Participants	Sample size: 20 adult participants were randomised Recruitment: Not reported Inclusion criteria ‐ diagnostic classification criteria: DSM‐IV Specific Phobia Inclusion criteria ‐ rating scales: Mini‐International Neuropsychiatric Interview (MINI), Snake Questionnaire Included disorders: specific phobia: snake phobia Co‐morbidities: 1 participant in DCS group had co‐morbid depressive disorder Gender: 40% male (both groups) Mean age: placebo group mean age 39.00 years (SD 13.91); DCS group mean age 34.60 years (SD 12.69) Ethnicity: 80% of placebo group was White; 60% of DCS group was White Pharmacotherapy during the study: Naturalistic prescribing allowed. 3 participants in placebo group were taking medication; 2 participants in DCS group were taking medication (types of medication not reported)
Interventions	Intervention: Participants received 50 mg of DCS 1 hour prior to 1 session of graded exposure therapy (N = 10) Comparison: Participants received placebo pill 1 hour prior to 1 session of graded exposure therapy (N = 10) Therapists: Not reported
Outcomes	Response; withdrawals; anxiety: Snake Questionnaire
Notes	Funding from industry: No, study was funded by departmental funds at Hartford Hospital Medication supplied by industry: Not reported Any author work for industry: No Study ID: NCT01450306
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Described as randomised, but does not report method of sequence generation
Allocation concealment (selection bias)	Unclear risk	Details of allocation concealment were not provided
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Subjects received DCS or "an identically packaged placebo capsule". Other details to assure blinding not reported
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Details regarding blinding of assessors not provided
Incomplete outcome data (attrition bias) All outcomes	Low risk	All randomised subjects participated in study and clinical follow‐up assessment
Selective reporting (reporting bias)	Low risk	All outcomes stated in protocol were reported
Other bias	Low risk	The study appears to be free of other sources of bias