Personality disorder, mental retardation and aggression are frequently encountered therapeutic problems in epilepsy patients.

This paper gives an overview of symptomatology and treatment of personality disorder, interictal aggression and mental retardation in epilepsy.

Literature review supplemented by clinical experience.

Personality changes in patients with epilepsy are often symptoms of an organic psychosyndrome. Aggression is not more frequent among epilepsy patients than in the general population, but if it does happen it is often more severe. There is a need for controlled treatment studies. A treatment strategy is suggested. In the mentally retarded, diagnostic instruments should be used to overcome diagnostic difficulties.

Prevalence studies based on DSM-IV personality disorder, conducted in the community, are needed, as well as systematic research on diagnosis and treatment of personality disorder in epilepsy patients. Randomized controlled trials (RCTs) considering the effectiveness and adverse effects of antidepressants and neuroleptics in epileptic patients with mental retardation are seriously needed. In the meantime, the Expert Consensus Guideline Series on Treatment of Psychiatric and Behavioural Problems in Mental Retardation is useful. The use of neuroleptics for the treatment of aggressive or destructive behaviour in nonpsychotic mentally retarded patients remains controversial.