Most of us are aware of the controversy surrounding concussions and football players — specifically, football players receive concussion after concussion, ultimately retiring from their careers with higher rates of depression, memory loss, and even suicide. Researchers have found signs of chronic traumatic encephalopathy, a disease caused by repetitive brain trauma, in 76 of 79 deceased NFL players including Dave Duerson, Junior Seau and other football players who had lost their lives to suicide. The phenomenon even has its own Wikipedia entry. (Sadly, football players who have committed suicide have their own Wikipedia entry as well.)
Concussions and other forms of traumatic brain injury aren’t limited to football players. In fact, traumatic brain injury is one of the major causes of death and disability in the United States. Approximately 1.7 million Americans sustain a traumatic brain injury each year, and 52,000 of those Americans die. Traumatic brain injuries make up nearly a third of all injury-related deaths.
But what about the people who don’t die? Like football players, are they at risk for suffering long-term psychological distress? Or are these consequences reserved for people who have experienced more severe forms of brain injury?
What is a traumatic brain injury?
Traumatic brain injury, often shortened to TBI, occurs when a sudden, external trauma causes damage to the brain. As an example, a woman who hits her head on a dashboard during a car accident would likely sustain a TBI. The infamous Phineas Gage, a man whose brain was pierced by a tamping iron during a railroad construction accident, also had a TBI. A stroke, on the other hand, would not be a TBI, since the damage originates internally rather than externally.
Between 2006 and 2010, the Centers for Disease Control and Prevention determined that falls were the leading cause of TBIs at 40 percent. Unintentional blunt force trauma — in other words, being accidentally hit by an object – was responsible for 15 percent of TBIs. Car accidents and assaults were the lowest at 14.3 percent and 10.7 percent respectively.
Some of the symptoms associated with traumatic brain injury are straightforward — a person who receives a blow to the head might lose consciousness, develop a headache, feel lightheaded or lapse into a coma. Other symptoms might seem a little unusual — for instance, TBI patients sometimes struggle with repeated episodes of vomiting or have one pupil larger than the other. Still other symptoms are subtle and may appear to be entirely unrelated to the injury. For instance, some people with TBI experience heightened levels of anxiety, depression, and mood swings.
Unfortunately, these latter symptoms often go ignored.
When traumatic brain injuries cause psychiatric symptoms
In 2013, a group of Danish scientists found that individuals with TBI (including concussions) were four times more likely to develop a mental illness. People who had received a TBI were 65 percent more likely to develop schizophrenia, 59 percent more likely to develop depression and 28 percent more likely to develop bipolar disorder. This study is the largest of its kind and involved following 1.4 million Danish citizens born between the years 1977 and 2000.
This study is far from the only one to suggest a link between TBI and mental illness. A research team led by Jonathan Godbout, an associate professor at Ohio State University, found that mice that had sustained a TBI demonstrated increased depressive symptoms as well as higher-than-normal levels of neural inflammation. (I have previously written about mental illness’ surprising link to inflammation). Yet another study found that experiencing depressive symptoms after a head injury is more common than not — the prevalence of depression after TBI is greater than 50 percent.
The most frightening piece of research, however, was published earlier this year: People who had received a concussion in the past were three times more likely to fall victim to suicide.
The risk of ignoring mild traumatic brain injury
Most of the people in the preceding research studies didn’t have severe traumatic brain injuries. Many of them had received only mild concussions and treated them in the way most people treat concussions: a short visit to the emergency room, bed rest, and painkillers. They were not war veterans or football players. They were individuals who left a car accident with just a headache and a sore neck, or a student athlete who underestimated the speed of a baseball.
The brain is a delicate organ and, unfortunately, it does not take much to knock its chemistry out of alignment. Even though receiving a concussion may be a tiny blip in most people’s memories, the ramifications of the injury can follow them for the rest of their lives.
As a doctor, I often ask my patients about head injuries because of how common they are. I ask not only the patients but also their close relatives and roommates. Once, I encountered a 39-year-old mother who presented with anxiety, depression, and psychotic symptoms. Although she claimed to have never suffered any head trauma, her mother remembered that, at the age of 5, she had been in a car accident and lost consciousness for more than 30 minutes. She later had a seizure. I placed the patient on an anticonvulsant, a drug designed to reduce seizures, and she soon reported a decrease in her symptoms.
If you’ve received a head injury, don’t ignore it. If you feel anxious or depressed after a concussion, don’t assume that the feeling is unrelated. Speak to your doctor. Get help. Traumatic brain injury doesn’t need to be an invisible illness.
Contributed to by Courtney Lopresti, M.S. Neuroscience