The influence of folate serum levels on depressive mood and mental processing in patients with epilepsy treated with enzyme-inducing anti-epileptic drugs.

BACKGROUND: Folate deficiency is common in patients with epilepsy and also occurs in patients with depression or cognitive deficits.
OBJECTIVE: This study investigates whether low serum folate levels may contribute to depressive mood and difficulties in mental processing in patients with epilepsy treated with anti-epileptic drugs inducing the cytochrome P450.
METHODS: We analysed the serum folate levels, the score in the Self Rating Depression Scale (SDS) and the results of a bedside test in mental processing in 54 patients with epilepsy.
RESULTS: There was a significant negative correlation between the serum folate levels and the score in SDS and significant positive correlations between the score in SDS and the time needed to process an interference task or a letter-reading task.
CONCLUSIONS: Low serum folate levels may contribute to depressive mood and therefore to difficulties in mental processing. Further studies utilizing total plasma homocysteine as a sensitive measure of functional folate deficiency and more elaborate tests of mental processing are required to elucidate the impact of folate metabolism on depressive mood and cognitive function in patients with epilepsy.