Binnie 1989.

Methods	Randomized, double‐blind, cross‐over study. Two treatment arms: 1 placebo, and 1 lamotrigine. Baseline period = 8 weeks.Treatment I and II = 12 weeks each. Washout = 6 weeks, including taper period.
Participants	Single centre study from Netherlands. 34 adults aged between 16 to 51 years (mean 37.1 +/‐ 10.26). 16 were randomised to lamotrigine and 18 to placebo during the first treatment phase. All had drug‐resistant partial seizures. The age of onset of epilepsy ranged from 1 to 40 (mean 14.3 +/‐ 10.7), the duration of epilepsy was 6 to 49.5 (mean 22.8 +/‐ 11) years. Maximum number of other AEDs = 4.
Interventions	Add‐on lamotrigine, or placebo. Median daily dose of lamotrigine was 200 mg. Participants on valproate received lower doses.
Outcomes	(1) 50% responder rates. (2) Withdrawal from study for any reason. (3) Adverse effects.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated random permuted blocks.
Allocation concealment (selection bias)	Low risk	Participants were allocated sequentially‐numbered sealed packages containing either lamotrigine or placebo.
Blinding (performance bias and detection bias) All outcomes	Low risk	Participants and parents were blinded. An unblinded investigator with knowledge of the medication and plasma concentrations instructed the blinded investigators about dispensing the trial medications. Identical tablets and packaging used.
Incomplete outcome data (attrition bias)	Low risk	No participants were excluded from analysis. No participant withdrew from the study during the first treatment phase.
Selective reporting (reporting bias)	Low risk	All outcomes stated in methods section of paper were reported in the results. There was no protocol available to check to priori outcomes.
Other bias	Unclear risk	This study was sponsored by GlaxoSmithKline, the manufactures of LTG.