Researchers find that one in six Ontario adults reports a history of TBI

Nearly seventeen per cent of adults surveyed in Ontario said they have suffered a traumatic brain injury that left them unconscious for five minutes or required them to be hospitalized overnight, according to new research. These same adults also reported more substance use, smoking and recent psychiatric distress.

Researchers compared the prevalence of reported TBI with current substance use, cigarette smoking and psychological distress among 1,999 Ontario adults.

"We found that one in six Ontario adults reported a history of TBI," said Dr. Gabriela Ilie, lead author of the study and a post-doctoral fellow at St. Michael's Hospital. "That prevalence is higher than previously known. Equally concerning, is the rate of harmful behaviours reported by adults with a history of TBI."

The study, published today in Journal of Neurotrauma, showed that compared to their peers, adults with a history of TBI reported that they were:

• 2.9 times more likely to have taken opioid pain relievers -such as Percocet, Tylenol-3 or codeine- without a prescription in the past year

• 2.8 times more likely to have smoked cannabis in the past year

• twice as likely to have smoked cigarettes every day in the past year

• nearly twice as likely to have described experiencing psychiatric distress - such as depressed mood, anxiety, insomnia, and social dysfunction - in the past four weeks

"Although our data can't show which came first, it's possible that those with a history of TBI may be turning to opioids, marijuana and nicotine as coping mechanisms to deal with the lingering effects of their TBI," said Dr. Ilie. "Of course, the reverse may also be true; someone who uses drugs may be more likely to behave in ways that risk suffering a brain injury."

The data used in the study were from the 2011 cycle of the Centre for Addiction and Mental Health's Monitor, a continuous, cross-sectional telephone survey of Ontario adults aged 18 and older.

"Medical practitioners should be aware of the potential association between substance abuse and brain injury," said Dr. Robert Mann, a senior scientist at CAMH and co-principal investigator of the study. "More research is needed, but it's possible that part of long-term TBI treatment may one day include screening for substance abuse and mental health problems to help address this issue."

Many studies use hospital admission records to estimate the prevalence of TBI, which omits TBIs where individuals did not seek medical attention. By combining hospital records and self-reporting, Dr. Ilie has shown that the prevalence of TBI is higher than previously known - possibly because many head injuries remain uncounted when they are not being reported to employers or health care workers.

In 2013, Dr. Ilie, Dr. Mann and other researchers showed similarly high rates of TBI and poor health behaviours among Ontario students between Grades 7 and 12.

"We now have data for adults and students from the same year," said Dr. Ilie. "Our research shows that, young or old, no one is immune from TBI and that substance abuse and psychiatric distress are often connected to brain injuries. Further investigation is needed to better understand TBI and its harmful health behaviours but our findings really reinforce the need for preventive action against TBI in Ontario."