Due to the difficulty in finding a mechanism of action for SUDEP that is common in most patients, it is difficult to assess what are the exact risk factors. A few similarities have been noted across many of SUDEP patients. These similarities include:
- Age: late 20s, early 30s
- Males
- Generalised tonic-clonic seizures
- High frequency of seizures
- Chronic epilepsy
- Symptomatic epilepsy (this may be the result of an underlying brain damage caused by accidents, tumours, infections, metabolic disorders)
- Structural brain lesion
- Post-traumatic epilepsy
- Recent unusually stressful life event
- Poor anti-epileptic drug compliance
- Psychotropic drug treatment (including for anxiolytic use)
- Alcohol
Other possible risks with conflicting evidence:
- Early onset epilepsy
- Developmental delay
- Poly-therapy of anti-epileptic drugs
Many websites have stated that some SUDEP cases have been observed to have sub-therapeutic levels of antiepileptic drugs. This has not been proven. There are many reasons for why the levels could be sub-therapeutic. People with well-controlled seizures could have sub-therapeutic levels of AEDs and still be at low risk for SUDEP. For this reason, often measurements of post-mortem AED levels in the blood can prove misleading.