EPILEPSY AND PSYCHIATRIC-DISORDERS - EPID EMIOLOGIC DATA

Data about psychiatric disorders associated with epilepsy as well as t heir risk factors are heterogeneous The overall prevalence of psychiat ric disturbances in epileptic patients can be estimated between 20 and 30 per cent. It is the highest in pharmocoresistant cases seen in spe cialized centers. Psychotic disorders, depression, and suicide are the three most common among interictal disturbances. Psychoses affect 2 t o 9 per cent of patients and are more frequent in cases with aura or a ltered consciousness, such as in complex partial seizures and absences . They correlate positively with the multiplicity of seizures but ofte n inversely with their frequency. Temporal lobe epilepsy is associated with schizophrenic-like and paranoid types of psychosis, but frontal lobe epilepsy is also common. A putative association with predominant left or bilateral EEG abnormalities in cases with partial epilepsy rem ains to be confirmed as well as the frequency of underlying structural lesions. Depressive disordes affect 20 to 60 per cent of patients. Wh ile their occurrence with partial complex seizures and left hemisphere fool is common, the role of temporal lobe involvement still appears c ontroversial. Depression prevails in cases with seizures that occasion ally, albeit rarely secondarily generalize and correlates with the dur ation of the disease, intractabable seizures, and polypharmacy. A gene tic factor is likely to play a role. Suicides rates are increased, enc ountered in 0,2-0,5 per cent of patients and causing deaths in 3-7 per cent of them. The overall risk might be the highest during the first years after diagnosis of epilepsy as well as in patients with temporal lobe foci, depression, or psychosis. Great variability and discordanc e in results show the major difficulties encountered in epidemiologic studies. Most of these problems relate to the classification oi epilep tic disorders as well as that of psychiatric disorders, the variabilit y in the methods and measures which are used, and frequent bias in the selection of patients. We review here data about the frequency of maj or psychiatric disorders in epileptic patients or the frequency of epi leptic disorders in psychiatric patients, and also possible risk facto rs related to the epileptic disease and its evolution.