In the year following a traumatic brain injury, roughly half of survivors likely experience a bout of clinical depression -- a rate almost eight times higher than that found in the general population, says a study published Tuesday in the Journal of the American Medical Assn. And those whose head trauma was followed by depression reported significantly more pain, greater mobility problems and more difficulty carrying out their usual responsibilities than those who were not plagued by post-injury depression.
Traumatic brain injury, or TBI, is sometimes called concussion. Often called the "silent epidemic," it affects some 1.5 million Americans yearly. Its symptoms are often subtle -- including personality changes, problems of memory and concentration, headaches and mood disturbances. While for most, the effects of a head trauma will clear within a year, many have more lasting effects. For at least 80,000 people a year, major disability will follow.
The 559 participants in this study had all come to a trauma center in the Seattle area with a head injury, signs of brain trauma that could be detected by a CT scan, and at least a few complications -- including loss of consciousness, disorientation or other factors that qualified them as scoring at most a 13 on the 15-point Glasgow Coma scale. Over the next six months, and then again at eight, 10 and 12 months after the participant's injury, researchers conducted a detailed telephone interview to gauge his or her mood state and ability to function. The result, said the researchers, was likely to yield a conservative picture of how many suffered from depression.
Past efforts to measure the rate of post-brain injury depression have been limited in their usefulness and yielded estimates that ranged from 10% to 77%. While this study included participants whose injuries ranged widely in severity, its findings clearly suggest that even those thought to have had a relatively mild injury had far higher rates of subsequent depression than would be expected had they remained unhurt. Among those whose injury was considered mild to moderate, 51.9% and 51.6% suffered from subsequent depression. Among those with severe brain injury -- as measured by the Glasgow Coma Scale -- 57.1% did.
In fact, the measures that physicians use to diagnose and treat brain injury were not very good predictors of whether a survivor would go on to suffer depression. Whether or not a victim had suffered bleeding in the brain or cortical contusions -- essentially, bruises of the brain's gray matter -- didn't make much difference in the likelihood of post-injury depression. That fact underscores the limits of what is understood about brain injury and its outcomes. (You can read more about what physicians are learning about brain injury -- much of it from the experience of U.S. troops in Iraq and Afghanistan but also on the playing fields of professional and college sports too -- here, here and here.)
Brain injury survivors who were depressed near or at the time of their accidents, who had suffered post-traumatic stress disorder or had any other past psychiatric diagnosis, and those who were intoxicated on cocaine or methamphetamine had far higher rates of post-injury depression. And victims were more likely to report depressive symptoms after their injury if they fit any of the following categories: they were African American, had not completed high school, or their injury was caused by violence (as opposed to a vehicular crash, fall or recreational injury). Also, those who were engaged in litigation associated with their injury were more likely to be depressed (65.5% vs 52.2%) than those who were not.
To learn more about TBI and its sometimes-persistent effects, this comprehensive website can't be beat. To learn about local support groups and national and state efforts to improve life for those with TBI, check this website out.