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People with epilepsy have an increased risk of drowning (15- to 19-fold) compared with the
general population. In a meta-analysis of the risk of drowning, the total SMR was 18.7. The SMR
varied depending on the population under study, with an SMR of 5.4 in community-based
incident cohorts, 18 in people with prevalent epilepsy, 25.7 in people with epilepsy and learning
disability and 96.9 for people in institutional care43.

People with epilepsy have been shown to be at increased risk of suicide in some studies13,21,44 but
not in others5,11. In a meta-analysis, the SMRs for suicide in people with epilepsy were markedly
elevated, particularly for those with temporal lobe epilepsy45. In a population-based control study
from Denmark, 2.3% of people with epilepsy committed suicide compared with 0.7% in the
general population, corresponding to a three-fold increased risk (risk ratio 3.2; 95% CI 2.9, 3.5).
This risk was particularly high in people with co-morbid psychiatric illness and in the first six
months following diagnosis46. A more recent meta-analysis found that the overall SMR for
suicide in people with epilepsy was 3.3 (95% CI 2.8, 3.7), with the highest rates being in those
following temporal lobe excision (SMR 13.9), following other forms of epilepsy surgery (SMR
6.4) and in people with temporal lobe epilepsy (SMR 6.6)47.

In a study48 looking at the role of psychiatric comorbidity in premature mortality in people with
epilepsy, people diagnosed with epilepsy in Sweden between 1969 and 2009 were identified
through the National Patient Register (n = 69,995) and compared with age-matched and sex-
matched controls (n = 660,869) and unaffected siblings (n = 81,396) for risks and causes of
premature mortality. During follow-up 6155 (8.8%) people with epilepsy died. A total of 972
people with epilepsy (15.8%) died from ‘external causes’ (suicide, accidents or assault) with a
high adjusted odds ratio (aOR) for non-vehicle accidents (aOR 5.5; 95% CI 4.7, 6.5) and suicide
(aOR 3.7; 95% CI 3.4, 4.2). While 75% of those who died from external causes had comorbid
psychiatric disorders with strong associations in individuals with depression (aOR 13.0; 95% CI
3.16, 6.0) and substance abuse (aOR 22.4; 95% CI 18.3, 27.3) compared to people without
epilepsy and no psychiatric comorbidity, the risk was also increased in people with epilepsy but
no depression (aOR 3.3; 95% CI 3.0, 3.7) or substance abuse (aOR 2.2; 95% CI 1.9, 2.6).

AEDs and increased mortality

It has been suggested that antiepileptic treatment with more than two AEDs increases the risk of
SUDEP49, though other studies have not shown an increased risk of SUDEP with any AED in
monotherapy or in combination therapy50. Moreover the risk of suicide in people taking AEDs,
although increased, appears to be low51.

It has been reported that long-term use of AEDs is associated with an increased risk of fractures,
particularly in women, with the risk increasing with the duration of treatment52.

The response to treatment has been suggested as a determinant of mortality, with people who
continue to have seizures despite treatment having an increased risk of premature death compared
with those rendered seizure free where no such risk was observed53.

Non-adherence to antiepileptic medication has been shown to be associated with an over three-
fold increased risk of death (hazard ratio 3.3; 95% CI 3.1, 3.5) after controlling for possible
confounding factors. Non-adherence was also associated with 86% increased risk of hospital
admission and a 50% increased risk of A&E attendance54.