More than just a bump on the head

Author:  Metcalfe David

Date:  February 2008

A bump on the head never makes you happy, and a paper in the Archives of General Psychiatry just discovered why. The article, led by Alain Ptito of the Department of Neurology and Neurosurgery at McGill University, has identified neurological changes in the brain following head trauma which can result in depression. This study goes some way toward explaining why 40% of head trauma patients suffer from depression, compared with 5% in the general population.

Prior to this study, according to Ptito, "very little was known about the neurological basis of the depression frequently reported by athletes following concussion." Indeed, most clinicians viewed post-trauma depression as a subjective illness; a view supported by the lack of neurological or cognitive deficits found in such patients.

The researchers used a new imaging technique called functional MRI (fMRI) which measures blood oxygen levels, allowing technicians to "detect areas of the brain with abnormal neural activity". They tested 56 male athletes, 40 of which had suffered concussion, and 16 of which were healthy and formed the control group. They found that 24 of the concussed athletes suffered from mild or moderate symptoms of depression. These patients were found to have reduced brain activity in regions associated with depression such as the striatum and dorsolateral prefrontal cortex. In addition, abnormalities were noted in the temporal and medial frontal regions. According to Ptito, "concussed subjects with depression presented the same pattern of brain activation as that seen for patients with major depression".

Although previous work had linked concussion with major depression later in life, this is the first time that researchers have found a neurological basis for this outcome. It may also provide a means of identifying head trauma patients who are at risk of developing depression early enough to commence intervention.

Written by David Metcalfe

Reviewed by Charley Wang

Published by Pooja Ghatalia