National Academy of Sciences: Long-Term Consequences of Traumatic Brain Injury.
A few findings:
Sufficient evidence of an association between (among other things):
- Moderate to severe TBI and long-term adverse social-function outcomes, particularly unemployment and diminished social relationships.
- TBI and depression.
- TBI and aggressive behaviors.
- TBI and postconcussion symptoms (such as memory problems, dizziness, and irritability).
Limited but suggestive evidence of a link between (among other things):
- Moderate or severe TBI and psychosis.
- TBI and decreased alcohol and drug use in the 1–3 years after injury.
Also interesting: Evidence is of insufficient quantity, quality, consistency, or statistical power to permit a conclusion regarding the existence of an association between mild TBI and long-term adverse social functioning, including unemployment, diminished
social relationships, and decrease in the ability to live independently.
(Mild TBI is manifested as a brief change in mental status or unconsciousness, whereas severe TBI results in an extended period of unconsciousness or amnesia.)