Forssell 2004.

Study characteristics
Methods	Design: cross‐over Duration: 4 weeks Assessment: baseline to post‐intervention Country: Finland
Participants	Pain condition: atypical facial pain Population: adults with atypical facial pain Minimum pain intensity: ≥ 3 on 0‐10 scale Inclusion criteria No clear pathology or somatic findings explaining the facial pain ≥ 3 on 0‐10 pain intensity scale Exclusion criteria Cardiac, hepatic, or renal disease Total participants randomised: 30 Age in years (median, range): 52 (38‐66) Gender: 12/30 were female Pain duration in years (mean, SD): NR
Interventions	Placebo n = 30 Inert Matched dosing schedule and identical appearance to antidepressants Venlafaxine 37.5‐70 mg n = 30 SNRI Flexible dosing based on tolerability
Outcomes	Pain intensity Mood Withdrawal
Missing data methods	Completer analysis only
Funding source	Non‐pharmaceutical: funded by Helsinki University Central Hospital Research Fund
Conflicts of interest	NR
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Participants were randomised using computer‐generated random numbers.
Allocation concealment (selection bias)	Low risk	Allocation procedure not specified
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double‐blind with identical appearance and matched dosing schedules
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Self‐reported outcomes from blinded participants
Incomplete outcome data (attrition bias) All outcomes	High risk	Completer‐only analysis Attrition Total: 10/30 (33.3%) Venlafaxine 37.5‐70 mg: 6/30 (20.0%) Placebo: 4/30 (13.3%)
Selective reporting (reporting bias)	Unclear risk	No protocol or trial registration found
Other bias	Low risk	No other sources of bias were identified.