The conclusion of a 35-year Swedish population study published in the December 27, 2011 online issue of PLOS Medicine was that TBI, but not epilepsy, increases the risk of violent crime. Researchers from the Centre for Violence Prevention at Sweden’s Karolinska Institute combined Swedish population registers from 1973 to 2009, and examined associations of epilepsy and traumatic brain injury with subsequent violent crime, defined as convictions for homicide, assault, robbery, arson, any sexual offense, or illegal threats or intimidation.
Each case was age and gender matched with 10 general-population controls. Cases were also compared with unaffected siblings to assess familial factors. After adjusting the numbers to account for confounding factors, the data showed that TBI significantly increased the risk of violent crime.