Folate metabolism in epileptic and psychiatric patients.

Serum and red cell folate levels and serum vitamin B(12) levels have been estimated in 33 normal controls; 34 epileptic outpatients, 19 of whom also suffered from psychiatric illness; 33 epileptic inpatients with psychiatric illness; and 30 non-epileptic inpatients with psychiatric illness. Significant lowering of serum folate and red cell folate levels was observed in epileptic patients with psychiatric illness, and a less significant fall in red cell folate levels was found in non-epileptic psychiatric patients. Serum folate levels less than 2·5 ng/ml. were found in two controls, seven outpatient epileptics, 29 inpatients, and 10 non-epileptic patients. Red cell folate levels less than 100 ng/ml. were found in two controls, nine outpatient epileptics, 23 inpatient epileptics, and seven non-epileptic patients. A significant correlation was found between serum and red cell folate values in control, epileptic, and non-epileptic patients. In the epileptic patients there was a significant association between low serum and red cell folate levels and the presence of psychiatric illness. The origin and possible significance of these findings are discussed.