Drs. Tomson and Mattson will utilize three nation-wide Swedish registries that offer unique opportunities to study the association between drug treatment and risk of sudden unexplained death in epilepsy (SUDEP). The medical records of living individuals with epilepsy will be compared to those with SUDEP with respect to use of antiepileptic drugs (AEDs) and other drugs to assess if the risk of SUDEP is related to non-adherence to prescribed AEDs, to any specific type of AED, and if concomitant use of other drugs such as some antidepressants could be protective. This study will provide essential information for the development of pharmacological treatment strategies to reduce the risks of and to prevent SUDEP.