Lammers 1991.

Methods	Double‐blind parallel randomised trial versus placebo: pre‐treatment period of 7 days; no run‐in period; treatment period of 28 days.
Participants	28 adult participants with narcolepsy (gender not known). Mean age 43 years (range 16‐67). Place of the study: The Netherlands (not specified ethnic composition of participants). Inclusion criteria: "typical EDS with sleep attacks and at least one of the accessory symptoms (cataplexy, hypnagogic hallucinations or sleep paralysis)". Exclusion criteria: not reported. Recruitment procedures: not reported. Not reported severity of the disease at inclusion. Pre‐trial treatment: 11 participants with no medication; 12 participants with psychostimulants; 6 participants with antidepressants; 5 participants with GHB; 3 participants with other drugs.
Interventions	16 participants allocated to ritanserin, dosage 2.5 mg bid. 12 participants allocated to placebo.
Outcomes	Considered in the review and present in the study: (1) Reduction of EDS according to objective laboratory test at the short term follow‐up. (2) Reduction of cataplexy measured by mean values of subjective ordinal scales at the short‐term follow up. (3) Adverse events by treatment groups. (4) Drop‐outs by treatment groups.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Unclear risk	Unclear
Allocation concealment?	Unclear risk	B ‐ Unclear
Blinding? All outcomes	Unclear risk	Unclear
Incomplete outcome data addressed? All outcomes	Low risk	All participants completed the trials; however 6 participants of the ritanserin group and 2 participants of the placebo group did not underwent the MSLT .
Free of other bias?	Low risk	Diagnosis was made on the presence of "typical excessive daytime sleepiness with sleep attacks and at least one of the accessory symptoms (cataplexy, hypnagogic hallucinations or sleep paralysis)" without reference to international diagnostic criteria. Cataplexy was not defined.