I forsøg for bipolar sygdom var mængden af hændelser numerisk, men ikke statistisk signifikant, større for lamotrigin (29/ 1212 [2, 4%]) sammenlignet med placebo (19/ 1054 [1, 8%]).
In the subset of bipolar disorder trials, the rate of events was numerically, but not statistically significantly, greater for lamotrigine (29/ 1212 [2.4%]) compared with placebo (19/ 1054 [1.8%]).