Coalition troops in Afghanistan are being attacked by roadside bombs at record levels, leaving Canadians soldiers with a legacy of traumatic brain injuries that health experts are grappling to understand.

And the mental toll of having to patrol bomb-seeded roads is expected to show itself in the years ahead in a spike in the number of soldiers with post-traumatic stress disorder, military officials say.

“The view is, clearly, when you’re involved with an IED (improvised explosive device), that you may have traumatic brain injuries,” said Maj.-Gen. Walter Semianiw, chief of military personnel.

“If you’ve been exposed to a (traumatic brain injury) the prevalence of then having PTSD may be higher. The facts are very clear,” he said in an interview.

“The biggest challenge is not here and today. It’s in five years and 10 years. Are they going to get the support they need?” Semianiw said.

As NATO forces launch offensives in southern Afghanistan, insurgents are fighting back with homemade bombs at levels never before seen in the eight-year-old conflict.

By the end of June, there had been 2,508 “incidents” involving IEDs this year, a 60 per cent increase over the same period last year, according to statistics from the Pentagon.

While Canadian commanders say the bombs are the weapons of cowards, they have proven effective nonetheless, sowing fear and chaos among civilians and soldiers alike.

Blast-induced brain injuries range from mild concussion to severe skull fractures and penetrating head wounds that can cause memory loss, anxiety, depression and post-traumatic stress.