In a proof of concept approach we propose studying the relation between epilepsy, depression, anxiety and stressful life events, using serum BDNF levels in patients with pharmacoresistant epilepsy. Evaluation of epilepsy type and co-morbid psychiatric profile will be performed in 150 subjects. By comparing BDNF levels for different epilepsy subgroups to BDNF levels for healthy subjects and for depressed subjects without epilepsy, we hope to identify whether risk of co-morbid depression and/or anxiety in epilepsy may be predicted using BDNF levels. In addition, in a subgroup of 25 patients, we propose a pilot study in which cortisol and C-reactive protein will be measured in addition to BDNF.