No one has a good estimate of the number of US prison inmates who have suffered traumatic brain injuries. The Centers for Disease Control estimates the portion of the male incarcerated population with these kinds of problems somewhere in their past at a frustrating 25 to 87 percent. It is clear that the percentage is far higher than the roughly 8.5 percent of the general population that reports traumatic brain injury.
The proliferation of head trauma adds another mental health challenge to America’s mess of a prison system. Depression and anxiety, substance abuse, violence and suicidal thoughts are all associated with head injuries. Cognitive impairment can also make prison life—rife with rules, jobs and social norms—more difficult, and the culture shock and byzantine prohibitions imposed by parole practically unbearable.