Blast effects on post-concussive and mental health outcomes: Data from Canadian Armed Forces breachers and snipers

LAY SUMMARY There has been increasing interest in understanding the impact of blast exposure on health and performance in military members and Veterans. This phenomenon has proven difficult to study because personnel diagnosed with blast-induced mild traumatic brain injury (mTBI) typically also exhibit emotional difficulties such as posttraumatic stress disorder (PTSD), likely because the events that led to mTBI in theatre were also emotionally traumatic. In turn, this comorbidity makes it difficult to tease apart symptoms uniquely due to blast-induced mTBI or PTSD. Researchers have therefore explored surrogate settings wherein the effects of blast exposure can be assessed in an operationally realistic, yet scientifically more controlled manner, such as breacher and sniper training. To that aim, researchers administered a measure of post-concussive symptomatology and two mental health scales to breachers and snipers, as well as sex- and age-matched military controls. The breachers and snipers reported greater levels of post-concussive symptoms, but not poorer mental health outcomes. Therefore, post-concussive symptoms and mental health outcomes might be dissociable when the impact of repetitive exposure to low-level blast is assessed in the context of training and operations, rather than following warzone deployment involving primarily high-level blast exposure.