Anderberg 2000.

Methods	Study setting: Single center study in Sweden Study design: Parallel Study duration: (1) duration wash‐out not reported, (2) 16 weeks titration and maintenance, (3) no follow‐up
Participants	Inclusion criteria: ACR criteria (1990) Exclusion criteria: Patients with severe heart diseases, such as angina pectoris or post‐heart infarct, as well as brain infarction, suicidal thoughts or who were seriously depressed (in need of immediate psychiatric care), and who took major or minor tranquilizers, major antidepressants or strong analgesics No separate demographic data for citalopram (N = 20) and Placebo (N = 19) reported; total sample: 100% women, mean age 49 years, race not reported; citalopram pain baseline FIQ subscale 6.6 (SD 2.2); placebo pain baseline FIQ subscale 6.6 (SD 1.9); no FIQ total scores reported
Interventions	Citalopram: 10‐40 mg/day p.o. Patients started with either 10 or 20 mg/day for the first week and increased the dose by 10 mg every fifth day up to either 30 or 40 mg/day Placebo: p.o. for 16 weeks Rescue medication: Paracetamol 500 mg twice daily or acetylsalicylic acid 1g twice daily were allowed Co‐therapies allowed or prohibited: No information provided
Outcomes	At least 30% pain reduction: Calculated by imputation method Global improvement: Not reported Fatigue: FIQ subscale VAS 0‐10 Sleep problems: Item reduced sleep of the Montgomery Asberg Depression Rating Scale Drop out due to adverse: Reported Serious adverse events: Not reported Depression: FIQ subscale VAS 0‐10; total score of Montgomery Asberg Depression Rating Scale not reported Pain: VAS 0‐10 Disease‐related quality of life: FIQ total score VAS 0‐80 not reported Physical functioning: FIQ subscale 0‐10 Anxiety: FIQ subscale VAS 0‐10 Tenderness: Myalgic score
Notes	Adverse effects were more common in the citalopram‐treated group as compared to the placebo one. The most commonly seen side effects were headache, nausea, fatigue, vertigo, sweating, sexual side effects and dry mouth. Three patients stopped citalopram treatment after the first dose due to severe nausea and severe dizziness Funding: Supported by public grants
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Randomisation was made at the medical products agency, and the investigator had a coded list"
Allocation concealment (selection bias)	Low risk	"The code was held secret to the involved investigators and patients until the end of study"
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	No information provided
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No information provided
Incomplete outcome data (attrition bias) All outcomes	High risk	Completer analysis for most outcomes
Selective reporting (reporting bias)	High risk	FIQ total score and total score of Montgomery Asberg Depression Rating Scale not reported
Group similarity at baseline (selection bias)	Unclear risk	No demographic data of citalopram and placebo group reported