Traumatic brain injury increases the risk of psychiatric illness.

MAIN RESULTS After one year, prevalence of psychiatric illness significantly increased in people with moderate to severe and mild traumatic brain injury, compared with controls (moderate to severe: 49%; mild: 34%; control: 18%; see table 1, http://www.ebmentalhealth.com/ supplemental). People with prior psychiatric illness are more likely to suffer from a psychiatric illness after traumatic brain injury. The effect of TBI on subsequent psychiatric illness, however, is greater among those without prior psychiatric illness (see table 2, http:// www.ebmentalhealth.com/supplemental).