Heckmann 2012.

Methods	Single centre, placebo‐controlled parallel RCT
Participants	20 BMS patients Overall ages not presented ‐ Group 1 (clonazepam): from text ‐ mean 67.5 (range 49‐89) / from table ‐ mean 65.0 SD: 12.4. Group 2 (placebo): from text ‐ mean 65.4 (49‐78) / from table ‐ mean 62.9 SD: 8.7 Sex: 13 F:7 M (F 65%:M 35%) Inclusion/exclusion and diagnostic criteria appropriate
Interventions	Intervention category: benzodiazepines Group 1: (n = 10) clonazepam 0.5 mg capsules ‐ 1 daily Group 2: (n = 10) placebo capsules ‐ 1 daily Duration: 9 weeks "As the intake of clonazepam can cause dependency, the medication was tapered off at the end of study in those subjects who had received verum. They took drops (0.1 mg clonazepam per drop) for a period of 10 days starting with five drops; this dose was reduced by one drop every 2 days"
Outcomes	Beck Depression Inventory (BDI) – 2 weeks before treatment, beginning of treatment, 3 weeks after starting treatment, at end of treatment and 2 weeks after end of treatment Zerssen Mood Scale – 2 weeks before treatment, beginning of treatment, 3 weeks after starting treatment, at end of treatment and 2 weeks after end of treatment Taste test score (0‐16): "Taste test. For quantitative assessment of gustatory function, a standardized validated test based on filter papers impregnated with tastants was used. Strips with the basic tastes sweet, sour, salty, and bitter (in four concentrations each) were applied onto the extended tongue, which was then taken back into the closed mouth. Before application of each taste strip, patients rinsed their mouths with water. Following presentation of the strip, patients were asked to identify the taste from a list of four descriptors (sweet, sour, salty, and bitter). The sum of correct identifications was used for further statistical analysis" ‐ performed 2 weeks before treatment and at end of treatment and 2 weeks after end of treatment (methods fully detailed in Mueller 2003: scale 0‐16 (each taste component 0‐4), higher better) Smell test score: "Smell test. The odour identification part of the Sniffin'‐ Sticks test battery were used to screen for changes in olfactory function. Following presentation of a common odour, subjects were each asked to identify it from a list of descriptors. The sum of correct identifications was used for further analysis" ‐ performed 2 weeks before treatment and at end of treatment and 2 weeks after end of treatment "Salivary flow rate. The salivary flow rate was measured using a cotton swab. It was weighed and placed onto the patient's tongue for 1 minute. After that, the cotton swab was weighed again and the resulting difference was used to calculate salivary flow rate" ‐ performed 2 weeks before treatment and at end of treatment and 2 weeks after end of treatment (methods fully detailed in Navazesh 1982: weight scale, higher better. Swab method is 1 of 4 methods (draining, spitting, suction, swab) compared to calculate salivary flow. (Note Navazesh 1982 authors state swab method is least reliable and most variable of the 4 options) Numerical pain ratings scale (0‐10): "Pain ratings. Patients rated the sensation of burning pain in the mouth on a scale ranging between 0 and 10, with 0 indicating no pain and 10 indicating maximum possible pain" ‐ performed 2 weeks before treatment and at end of treatment and 2 weeks after end of treatment
Source of funding	Study authors reported no funding was received
Notes	SES: not reported Conflict of interests: authors reported no conflict of interests exist Data analysis: ITT
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quotations: "performed by an independent individual using a specialized software program (RANDLIST; DatInf, Tübingen, Germany)"; "enrolment numbers were established, and the subjects to be investigated were randomized in such a way as to form five groups made up of four participants each (i.e., two were assigned clonazepam and two were assigned a placebo)" Comment: appropriate method
Allocation concealment (selection bias)	Low risk	Comment: randomisation and blinding was conducted by an independent person
Blinding (performance bias and detection bias) Blinding of participants	Unclear risk	Quotations: "The bottles were sealed and labelled with the study code and the enrolment number"; "When the study was complete, unblinding was carried out by an independent individual" Comment: it is unclear to the review authors at what point was the "study complete"; was it at the end of treatment or at the final session 5 visit? According to the data provided, the participants were unblinded for the outcomes taken during the final (session 5)
Blinding (performance bias and detection bias) Blinding of outcome assessors	Unclear risk	Quotation: "When the study was complete, unblinding was carried out by an independent individual" Comment: according to above comment, the investigators were still blinded at the session 5 assessment point. Again there was uncertainty about when exactly study completion occurred
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: all prespecified outcomes were reported in the prespecified way
Selective reporting (reporting bias)	High risk	Comment: side effects were not mentioned as a prespecified outcome and were not adequately reported in the outcomes ("The drugs were tolerated very well by all participants"; "does not cause major side effects"). This comment would suggest that some side effects were noted, but not formally reported. One would expect side effects from clonazepam and should be able to expect that side effects would be more thoroughly reported, as side effects may have unblinded participants
Other bias	Unclear risk	Comment: discrepancy between baseline ages of participants when comparing text and table data