[Mood disorders and epilepsy surgery: A review]

Historically, there is a strong link between depression and epilepsy. Patients with epilepsy are four to five times more likely to develop a depressive syndrome. It seems that the link between epilepsy and depression is bidirectional. There is little data on mood disorders secondary to epilepsy surgery. The goal of epilepsy surgery is to reduce the number and frequency of attacks, which in turn would allow improvements in mood disorders and cognitive impairment.

A systematic search of the international literature was performed using the bibliographic search engines PubMed and Embase. The following MESH terms were used: epilepsy surgery AND (depression OR depressive disorder OR mood disorder). We also used the "related articles" of PubMed, bibliography surveys, conference abstracts and Google Scholar to identify additional relevant papers.

Of the 130 studies found by the systematic search, 112 are excluded because they did not take into account the mood disorders secondary to epilepsy surgery. Fifteen studies are included in this review of the literature with a case study. Depression is the psychopathological condition that is the most frequently studied. According to several studies, the prevalence of depression is approximately 30% with nearly 70% of cases diagnosed during the first three months following epilepsy surgery. The majority of patients presented depressive symptoms during the first 3 to 12months after epilepsy surgery. In these studies, the risk of developing depression is correlated with the existence of previous depressive elements relative to the epilepsy surgery. A small number of studies reported cases of de novo depression. Studies have shown a correlation between very good to excellent control of epileptic seizures and a persistent improvement of mood disorders. It would seem that depressive symptoms post-surgery are more common when the surgical intervention concerns the temporal lobe and in particular mesial resections. There are only very few cases of maniac episodes. Hamid et al. showed an increased risk of suicide waning after the epilepsy surgery over a period of 5years.

Mood disorders are common psychiatric comorbidities in epilepsy surgery. The detection, prevention, and treatment of these symptoms in patients eligible for epilepsy surgery pose major challenges for psychiatrists and neurologists, requiring their close collaboration.