Depression, Stress and Vulnerability Factors in Drug Resistant Focal Epilepsies
Depression, Stress and Vulnerability Factors in Drug Resistant Focal Epilepsies
Psychiatric disturbances, notably depression, occur frequently as co-morbid conditions with
 epilepsy. A complex, probably bidirectional relationship between epilepsy and depression has
 been postulated. Both epilepsy and depression also interact with stressful life events, but
 only some patients develop these disorders after a stressful event, indicating the
 possibility of a "vulnerable" population. Animal and human studies have looked at the role of
 brain derived neurotrophic factor (BDNF) in this context. Low serum and/or CSF levels of BDNF
 are associated with higher incidence of depression, and thus indicate the vulnerable
 population.

 Animal studies of BDNF have looked specifically at the relation between epilepsy and
 depression using a novel "double hit" design. After chronic stress exposure, measurement of
 BDNF levels allowed identification of 2 sub-groups: a vulnerable population and
 non-vulnerable population. A "second hit" of kainic acid induced status epilepticus (SE) was
 then applied to both the vulnerable and non-vulnerable populations. Only the vulnerable
 population exposed to SE developed a depression-like profile.

 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.
Inclusion Criteria:

 -  Definite diagnosis of epilepsy, of any type (partial or generalised) and at any stage
 from diagnosis onwards

 -  Known or unknown etiology (symptomatic or cryptogenic epilepsy)

 Exclusion Criteria:

 -  Psychogenic non-epileptic seizures

 -  Psychotic disorders and bipolar disorders