Objective: To examine whether prior suicidal behavior and familial predisposition to psychiatric disorders modify the association between antiepileptic drug use and completed suicide.
Methods: Using the Danish National Prescription Register, we identified all incident users of antiepileptic drugs aged 15 years or older in Denmark between July 1997 and December 2015. We carried out a nested case-control study and defined exposure to antiepileptic drugs at the index date (ie, time of suicide). Conditional logistic regressions were used to estimate mortality rate ratios (MRRs) of suicide in current versus previous users of antiepileptic drugs. We also analyzed suicide risk associated with the 9 most commonly used antiepileptic drugs.
Results: We identified 1,759 individuals completing suicide. Current versus previous use of any antiepileptic drug was associated with an increased risk of suicide (MRR = 1.26, 95% confidence interval [CI] = 1.13-1.40). This excess risk was observed in individuals with a history of suicidal behavior (MRR = 1.28, 95% CI = 1.07-1.54) and in those without (MRR = 1.26, 95% CI = 1.11-1.43), and in individuals with a familial predisposition to psychiatric disorders (MRR = 1.48, 95% CI = 1.18-1.87) and in those without (MRR = 1.21, 95% CI = 1.07-1.35).
Interpretation: Use of antiepileptic drugs was associated with an increased risk of suicide. The findings do not support that the risk of suicide following treatment with antiepileptic drugs identified in randomized trials is explained by prior suicidality or familial predisposition to psychiatric disorders. The additional risk of suicide associated with use of antiepileptic drugs was generally low and should be balanced against benefits of treatment. ANN NEUROL 2019;86:951-961.
© 2019 American Neurological Association.