Role of Anxiety and Depression in Epilepsy

A Clinical Application of Anxiety and Depression as Related to Stress and Seizures


During her presentation, Dr. Silton outlined her research regarding depression and anxiety, which both influence a network of brain regions including the pre-frontal cortex and anterior cingulate cortex. As Dr. Silton stated, according to DSM guidelines, a categorical diagnosis of major depressive disorder requires five of nine criteria to be met, symptoms that endure for a minimum of two weeks, and an impairment in quality of life or daily activities. In contrast, generalized anxiety disorder is characterized by indecisiveness or a diminished ability to concentrate. Dr. Silton's claim that these two disorders may be intrinsically related is furthered by a study conducted by Michael Privitera from the University of Cincinnati.

Dr. Privitera's study suggested that stress, potentially linked to generalized anxiety or major depressive disorders, could fuel epilepsy and trigger seizures. Patients who believed that stress was having an effect on their epilepsy were labeled as "stress positive" and provided information regarding their experiences with epilepsy, level of stress, and history of depression or anxiety. There were a significantly lower amount of "stress negative" patients, who reported that stress did not effect their seizure activity. Interviews revealed that many of the patients had already tried a variety of stress-reduction techniques, such as yoga, and of those, "71% of them thought their seizures subsequently improved". (Anderson)

Findings of the study suggested that not only could "stress positive" patients sometimes predict the onset of a seizure, but also demonstrated a correlation to higher levels of depression and anxiety (as quantifiable via GAD scores and Neurological Disorders Depression Inventory for Epilepsy). In fact, findings of another study conducted by Dr. Allendorfer from the University of Alabama - Birmingham noted that "increases in brain activation were seen bilaterally in the superior temporal gyrus, posterior cingulate, and parietal areas, and unilaterally in the left insula" for patients who were "stress positive". (Anderson)

Moreover, such investigations and findings are further applicable to Dr. Silton's research, which looked at activity in the dorsal-lateral prefrontal cortex and anterior cingulate cortex with varying levels of depression via admission of the Stroop task. This is significant in that it highlights another potential factor, regarding the severity of the disorder, to consider for these patients, and even goes as far as to offer potential ways to measure these varying levels. It would be interesting to see whether the severity of the disorder effects the effectiveness of stress-reduction therapies for patients who are identified as "stress positive". 

Sources: 
Article: http://www.medscape.com/viewarticle/775751
Photo: http://www.personal.psu.edu/ekl126/assign6.html