A general practice-based prevalence study of epilepsy among adults with intellectual disabilities and of its association with psychiatric disorder, behaviour disturbance and carer stress

BACKGROUND: Although the elevated occurrence of epilepsy in people with intellectual disabilities (ID) is well recognized, the nature of seizures and their association with psychopathology and carer strain are less clearly understood. The aims were to determine the prevalence and features of epilepsy in a community-based population of adults with ID, and to explore whether the presence of epilepsy was associated with greater psychopathology or carer strain.

METHODS: Data were collected on the age, gender, place of residence, adaptive and challenging behaviour, social abilities and psychiatric status of 318 adults from 40 general practices, together with the degree of malaise and strain of family carers. For participants with epilepsy, a nurse collected information on seizures, investigations, treatment and carer concerns by interview. Association between epilepsy and psychiatric morbidity, challenging behaviour and caregiver malaise or strain, was explored by comparing those with epilepsy with a comparison group matched on adaptive behaviour.

RESULTS: Fifty-eight participants (18%) had epilepsy: 26% were seizure free, but 34% had extremely poorly controlled seizures. Earlier onset and seizure frequency were associated with adaptive behaviour. Carer concerns were related to seizure frequency and a history of injury. There were no significant differences in psychopathology, carer malaise or caregiver strain between the matched epilepsy and non-epilepsy groups.

CONCLUSIONS: This study supports the high occurrence and chronicity of epilepsy among people with ID. While psychopathology and carer strain is common within this population, underlying disability-related factors appear to be more important than the presence of epilepsy per se.