Adding to this site’s combat sports safety study archives, a study was recently published in the Journal of Head Trauma Rehabilitation suggesting that athletes exposed to repetitive head impacts that develop depression may be facing further cognitive impairments in the future.
In the recent study titled The Relations Among Depression , Cognition and Brain Volume in Professional Boxers, the authors were looking to see if there was a relationship between depression/cognitive changes and reduced brain volume to athletes that sustained repetitive head impacts. A total of 205 professional boxers participated in the study. The authors found there was indeed such a link. Interestingly the study also noted that depression may precede further cognitive changes meaning, from a regulatory perspective, that depression may be a key warning sign that an athlete may have sustained too much cumulative brain trauma.
The full abstract reads as follows:
Objective: Depression, neuropathology, and cognitive decline are commonly observed with repetitive head injuries (RHIs). We examined whether in boxers (a) clinically significant depression is associated with structural brain changes and cognition; (b) minimal symptoms of depression moderate the relations among RHI and brain volumes and cognition; and (c) baseline depression is associated with longitudinal cognitive changes.
Setting: Clinical Research Center.
Participants: A total of 205 male professional boxers.
Design: Cross-sectional and longitudinal (subsample: n = 45; first visit to follow-up range = 1-6 years; mean = 2.61 years).
Main Measures: Patient Health Questionnaire-9 depression; CNS Vital Signs cognitive battery; brain imaging.
Results: Clinically significant depression was associated with smaller regional volumes in insula, cingulate, orbitofrontal cortex, thalami, and middle corpus-callosum subregions; and with poorer verbal memory and psychomotor speed performance. Depression symptoms moderated the relations between RHI and bilateral thalami, left hippocampus, left medial orbitofrontal cortex, and bilateral insula volumes; but not cognition. Baseline depression was associated with poorer psychomotor speed and reaction time longitudinally and improved verbal memory performance longitudinally.
Conclusion: Clinical depression is associated with volumetric and cognitive changes occasioning RHI exposure, and even minimal depressive symptoms may moderate the relations between exposure and brain volumes in key regions. Longitudinally, there is preliminary evidence that depression precedes cognitive changes.