ARTICLE IN BRIEF
In a retrospective study, people with traumatic brain injury (TBI) who had different kinds of medical contacts — inpatient treatment, outpatient visits, and visits to emergency units — had an increased risk for suicide compared with those in the general population without TBI.
A new study on traumatic brain injury (TBI) and suicide risk — notable for its size and the level of detail of its analysis — has found that those who've experienced a TBI are almost twice as likely to commit suicide as those who have not had such an injury, with the highest risk seen among those who developed a psychological illness or engaged in non-fatal self-harm after their TBI.
Independent experts say that while the results, published in the August 14 JAMA, might not be groundbreaking — this increased risk has been seen in prior studies — the study provides a new and persuasive impetus for clinicians to include a psychiatric or psychological component into the treatment of these patients and to screen for suicide risk among people with brain injuries.
The study's lead author, Trine Madsen, PhD, a post-doctoral fellow at the Danish Research Institute for Suicide Prevention, said she hopes the main takeaway is that it is important to take steps to avoid TBIs altogether.
“First and foremost, we would recommend a focus on preventing TBI, such as promoting use of protective helmets in workplaces where risk of falls or head injury are higher, [such as] construction sites, and in contact sports like boxing and American football,” she said. “If head trauma has occurred, an individual who experiences post-TBI emotional problems or psychiatric symptoms should be advised to seek help or treatment for this in order to prevent a detour towards suicidal ideation or behavior.”
She said the findings also suggest it's important to schedule regular follow-up visits after discharge for a TBI.
Investigators analyzed data from 1980 to 2014 on more than 7.4 million people living in Denmark. They pulled information from the Danish Civil Registration System, the Database for Integrated Labor Market Research, the National Hospital Register, the Psychiatric Central Research Register, and the Cause of Death Register, all of which contain continuously updated data.
TBI data have been kept for inpatient treatment in Denmark since 1977. TBI information for outpatient visits and emergency room visits were not added until 1995, which could mean, the authors said, that the estimates for TBI-associated suicide risk is likely on the conservative side.
The suicide risk for those with one or more TBIs was 90 percent higher than those without a TBI, with an incidence rate ratio (IRR) of 1.90 after adjustments for 12 factors, including sex, age, socioeconomic status, marital status, fractures not involving the skull or spine, epilepsy, and psychiatric diagnosis or deliberate self-harm before the TBI (p<.001).
The more severe the TBI, the higher the risk, researchers found. For mild TBI, the IRR was 1.81; for skull fracture, 2.01; and for severe TBI, 2.38 (p<.001 for all).
People who were diagnosed with a psychological illness after their TBI were almost five times as likely to commit suicide as those with a TBI only (IRR, 4.90), and those who engaged in deliberate self-harm after TBI were more than seven times as likely (IRR, 7.54) to commit suicide.
Researchers found that the risk was highest in the six months immediately following the TBI and when patients had spent three or more days in treatment for TBI. Younger patients — those who were 16 to 20 at the time of their first contact with health care for TBI — had the highest suicide risk of all the age groups, investigators found.
Those who had a diagnosis of a psychological illness before TBI (IRR, 2.32) and those who had engaged in deliberate self-harm beforehand (IRR, 2.85) were at an increased suicide risk compared those with TBI only.
Further investigation on how to avoid steps leading to suicide after TBI would be valuable, Dr. Madsen said.
“It is important to look into how to optimize the treatment of serious head injuries to minimize the many possible consequences — psychiatric, cognitive, physical, and social — that can tragically lead to suicidal behavior,” she said. “It would be interesting to carry out a large register-based study examining how TBI might be associated with more social consequences such as employment status in the years following the TBI incident.”
Amy J. Starosta, PhD, assistant clinical professor in the department of rehabilitation at the University of Washington, said: “I think this type of research is really important because it just shows that we're not looking at one specific type of population, like veterans,” she said. “This is a problem for all of our rehab patients, and it's something that we need to be thinking about across the board in primary care settings, in rehab medicine clinics, in inpatient rehab settings, and in neurology clinics.”
In an accompanying editorial, Lee Goldstein, MD, PhD, associate professor of psychiatry and neurology at Boston University and Ramon Diaz-Arrastia, MD, PhD, director of the Traumatic Brain Injury Clinical Research Center at the University of Pennsylvania, wrote that the study was particularly notable for its adjustments for so many relevant factors, distinguishing it from past research.
“The results reported by Madsen, et al, point to an important clinical triad — TBI history, recent injury (especially with long hospital stays), and more numerous post-injury medical contacts [for example, inpatient and outpatient hospitalization] for TBI — that serves as ‘red flags’ for increased suicide risk,” they wrote. They also noted that suicide risk is relevant across all TBI severity levels, including the “far more common mild injuries,” for which the incidence rate ratio, compared to no TBI, was 1.81.
While the results are clinically relevant, they said, they are also “mechanistically indeterminate.”
“Among the main questions stimulated by this research is the mechanism,” they wrote. “How exactly do TBIs increase suicide risk? What are the substrates and processes that causally link TBI, a highly heterogeneous condition, to a singular catastrophic outcome? The answers are undoubtedly multifactorial and complex.”
Dr. Starosta said she was struck by the stark difference in suicide risk by gender among those with a TBI — 27.5 suicides per 100,000 person years for women and 49.3 for men — because some literature has suggested that there is much less of a difference by gender in TBI populations compared to the general population.
She said it was also telling that those with a pre-existing psychological illness actually had a lower suicide risk after they had a TBI.
“These patients have more of a touch-point with providers and I think that just really speaks to the intervention piece,” she said. “Having more touch points with a broad range of providers is going to be a really critical piece for actually making a change in suicide risk.”
She said that evaluating suicide risk among those who've had a traumatic brain injury is similar to the assessment in the general population, involving questions about depression, anxiety, hopelessness and other signs. But among those with a TBI, the conversation might be shaded a bit toward attention to patterns of impulsivity, which can be elevated among those who have had a TBI.
She said that more centers have integrated psychiatric and psychological components into their care, but outside of academic medical centers and some primary-care settings it has been a bit slow in coming, mainly because of limited resources.
“Once the screening — the initial questioning — has happened, you need to get a more fine-grained assessment, and that's really where having mental health available to medical providers is a really important key,” Dr. Starosta said. “It's reasonable for clinics, and providers and nurses to be screening for suicide either through standardized measures such as the Patient Health Questionnaires 2 and 9. But then at that point once we need to do a more though risk-assessment it's really helpful to have psychology, mental-health providers, or social work to be on board so that we have people who have that training.”
Craig Bryan, PsyD, assistant professor of clinical psychology at the University of Utah, said greater adoption of scientifically-supported suicide prevention treatments is needed. “I would argue that the treatment of suicide risk among all populations, even those without TBI, has been lacking,” Dr. Bryan said.
Both dialectical behavior therapy — which involves individual and/or group therapy that focuses on psychosocial issues — and brief cognitive behavior therapy — which addresses thoughts, beliefs, and attitudes and the development of personal coping strategies that target current problems — have been shown in many studies to reduce suicidal behaviors by 50 percent or more, he said. A 2015 study on which he worked found that cognitive behavior therapy was effective in a military population, a group with high rates of TBI.
“Although TBI was not an explicit focus of that study, the fact that a treatment was so effective in a population with high rates of TBI suggests brief cognitive behavior therapy may be a useful method for addressing suicide risk among TBI patients,” Dr. Bryan said.
He said that because similar results have been found in other studies, he doubted these latest findings would “change anything dramatically.”
But, he said, “it provides further evidence for the TBI-suicide link and may help to call attention to the need for clinicians to better implement empirically-supported treatments for suicide prevention. The aforementioned treatments — dialectical cognitive therapy and brief cognitive behavior therapy — seem to work because they help individuals to manage their emotions more effectively, take perspective, and improve decision-making in the midst of intense emotional distress. These are common problems that TBI patients report, so there may be some implications for the value of those treatments with this population.”