Siegmund 2011.

Methods	Design: Randomised, double‐blind, placebo controlled study Study duration: 1 month Follow‐up: 5 months Country: Germany
Participants	Sample size: 44 adult participants eligible and agreed to participate Recruitment: Not reported Inclusion criteria ‐ diagnostic classification criteria: primary diagnosis of panic disorder with agoraphobia, DSM‐IV Inclusion criteria ‐ rating scales: Clinical Global Improvement Scale (CGI‐I) Included disorders: panic disorder with agoraphobia Co‐morbidities: Not reported, though "severe other mental disorders" excluded Gender: DCS group 40% male; comparison group 68% male Mean age: DCS group 37.85; comparison group 37.32 Ethnicity: Not reported Pharmacotherapy during the study: Naturalistic prescribing allowed; 9 participants were taking an antidepressant, 1 participant was taking 2 antidepressants, 2 patients were taking benzodiazepines, 2 participants were taking an anti‐depressant and a benzodiazepine, and 1 participant was taking pregabalin
Interventions	Intervention: Participants received 50 mg doses of DCS administered 1 hour prior to 8 sessions of group exposure therapy plus three individual exposures (n = 20) Comparison: Participants received placebo pill administered 1 hour prior to 8 sessions of group exposure therapy plus three individual exposures (n = 19) Therapists: Therapy conducted by a certified psychologist accompanied by a co‐therapist
Outcomes	Withdrawals; anxiety: PAS (data points derived from graph); co‐morbid depression: BDI (data points derived from graph); co‐morbid anxiety: BAI (data points derived from graph); adverse events
Notes	Funding from Industry: No. This work was funded by a research grant of the German Federal Ministry of Education and Research to Andreas Ströhle (01GV0612). Medication supplied by industry: Unclear ‐ 50 mg of d‐cycloserine (Seromycin, Eli Lilly, USA) Any authors work for industry: Yes Study ID: ISRCTN44960833
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	'Randomisation was performed by pharmacy which prepared the study medication using the method of randomly permuted blocks of pairs.'
Allocation concealment (selection bias)	Low risk	'The study medication was handed out by the study staff in consecutive numbers, according to the individual time arrangements for exposure therapy (next exposure received next container). The randomisation sequence was kept in the pharmacy inaccessible to study staff until the last follow‐up data had been assessed and monitored.'
Blinding of participants and personnel (performance bias) All outcomes	Low risk	'All study staff (including those who did recruitment, assessments and therapy) and all participants were blind to the random allocation sequence.'
Blinding of outcome assessment (detection bias) All outcomes	Low risk	'All study staff (including those who did recruitment, assessments and therapy) and all participants were blind to the random allocation sequence.'
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, n = 2 in DCS group declined to participate in intervention, in placebo group n = 3 did not participate, n = 2 due to family problems and n = 1 worried about possible side effects. At 5 months post‐treatment, n = 4 lost for DCS group, n = 2 for further cognitive and behavioural therapies, n = 1 further pharmacotherapy, n = 1 for further pharmacotherapy and cognitive and behavioural therapies. In placebo group,n = 4 lost at five months, n = 3 for further pharmacotherapy and n = 1 for further pharmacotherapy and cognitive and behavioural therapies
Selective reporting (reporting bias)	Low risk	All outcomes stated in the protocol were reported on with data provided
Other bias	Low risk	No sources of other bias were identified