Substance abuse and traumatic brain injury (TBI) have a complex causal relationship. People with substance abuse issues are more likely to sustain a TBI, and people with a TBI are more likely to abuse substances. For example, for those treated for injuries in the Emergency Department, the likelihood of having a TBI increases significantly as blood alcohol increases. Likewise, patients with a history of TBI are more likely to have severe substance use disorders, more prior treatment episodes, earlier age at first use, greater medical and psychiatric co-morbidity and poorer outcomes.
While there is debate about whether the same environments might foster risk for both substance abuse and TBI, some kinds of injuries are associated with the greatest risks for substance abuse. A severe adult TBI, a mild TBI in adolescence, a TBI between the ages of 6-10, and multiple mild injuries are associated with greater severity of alcohol use disorders. Patients who had a TBI before age 6 tend to have more complicated substance abuse disorders, as well as greater cognitive difficulties.
Corrigan JD, Bogner J, & C Holloman. Lifetime history of traumatic brain injury among persons with substance use disorders. Brain Injury. (February 2012).