Max 1992b.

Methods	Crossover design, six weeks. Two six week periods, two week washout, no carry over effect (four week titration to max tolerated dose then stable dose). Patients were randomised to two different studies (Max 1992a and b). 37 randomised + 17 additional non‐randomised patients. 17 non randomised patients were excluded from analyses, only first period results available Randomisation methods not stated, blinding not clear Inclusion criteria: duration of symptoms at least three months.
Participants	Diabetic neuropathy of 4 years (range 0.5 to 12). 54 participants (27 final number in first period analyses: 12 on in fluoxetine group and 15 in placebo group). Mean age 58 (range 25 to 84), 31 male and 23 female patients
Interventions	Fluoxetine dose escalation from 20 mg to 40 mg daily orally (40 mg for all patients, except one); or active placebo benztropine from 0.125 mg to 1.5 mg daily orally, mean dose 1.3 (0.2 mg)
Outcomes	Pain patients reported, VRS Pain score decreased on fluoxetine 0.35 (0.11), on placebo 0.15 (0.07)
Notes	Dropouts 8/54(5 SE, others not reported) SE: 29/46 on fluoxetine, 31/46 on placebo Withdrawn due to SE 3/46 on fluoxetine (1 orthostatic hypotension, 1 headache, 1 rash), 2/46 on placebo (1 fatigue, 1 chest pain) QS = 1 (R1, DB0, W0)
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Unclear risk	B ‐ Unclear