August 14, 2018

expert reaction to traumatic brain injury and suicide

A paper published in JAMA looked at the association between risk of suicide and having sought medical attention for traumatic brain injury.

Dr Simon Fleminger, Consultant Neuropsychiatrist, Royal College of Psychiatrists, said:

“This is a strong study based on hospital record register of all 7.4 million people over the age of 10yr. living in Denmark over the 34 year period from 1980.  Of these 568,000 suffered a traumatic brain injury and 34,500 died by suicide. In those who had suffered a traumatic brain injury the risk of subsequently dying by suicide was approximately doubled compare with the rest of the population (41 vs 20 per 100,000 person years). The risk is a little less in those who suffered a mild TBI compared with a severe TBI.

“This is good quality research backed up by robust findings that confirm findings from earlier studies.  The research was able to extend these findings by showing that the risk of suicide was greatest in the first six months after the TBI, and that longer periods of stay in hospital at the time of the TBI, and a greater number of medical interventions, augmented the risk of suicide.  Unsurprisingly the risk of suicide in those who had suffered a TBI was much greater in those who had suffered a psychiatric disorder before their injury.  But the study did not attempt to look at substance misuse, something that is particularly associated with suicide and did not fully take into account the role of pre-injury personality characteristics.

“The press release is a fair description of the results.  The release might like to note:  The study found that those who suffered a fracture but not involving the head, were a little more likely to die by suicide than the rest of the population.  This suggests that some, but not much, of the increased risk of suicide after a Traumatic Brain Injury (TBI) is because of pre-injury personality characteristics that both increased the risk of suicide and increased the risk of TBI.

“The main implications are that over the 25 years after a TBI, a person has about a 1% risk of dying by suicide compared with a 0.5% risk in those not suffering a TBI. Second, that the attributable risk of TBI as a risk for suicide overall is about 5%; i.e. about one in twenty suicides are perhaps because the person has suffered a TBI.”

Dr Rina Dutta, Clinical Senior Lecturer King’s College London and Consultant Psychiatrist, said:

“An increased risk of suicide was associated with those residents of Denmark who sought medical attention for traumatic brain injury (TBI) compared with the general population without TBI in a study that used data from Danish national registers.

“The press release is concise but accurately reflects the science.  The research is of high quality and concludes that head-injury survivors – even from the milder end of the injury spectrum – are at higher risk of suicide than those without head-injury.  The study conclusions are backed up by solid National Population data based on more than 7 million people in Denmark.

“The researchers considered ‘traumatic’ to mean any contact with health services for a head injury, and then graded the contacts into 3 tiers of severity.  Concussion was the mildest, a skull fracture without a recorded head-injury was moderate and the most severe category was head injury where there was structural damage to the brain. Individuals with a health service contact for any type of head injury had nearly double the risk of suicide compared to those with no contact with head injury.  As expected those people with more severe head injury were at slightly higher risk of suicide compared to those with concussion.

“The paper addresses two important public health issues.  Each year, 1.4 million people attend emergency departments in England and Wales with a recent head injury. Between 33% and 50% of these are children aged under 15 years. Annually, about 200,000 people are admitted to hospital with head injury. Of these, one-fifth have features suggesting skull fracture or have evidence of brain damage.  Undue alarm about a prior head injury is not helpful however, because the majority of those who have sustained one will not end their life by suicide – it is doubling the chance of a thankfully rare occurrence.

“A novel and important finding is that the risk of suicide is particularly high in the first 6 months after a health service contact with head injury and the risk tapers off over time.  Studies prior to this had not shown a specific risk period for suicide.  Suicide risk was also associated with how many contacts someone has had with health services regarding head-injury.  The more contacts for head-injury, the higher the risk of suicide.  This will be helpful to clinicians who must keep in mind head-injury, particularly if recent, and also frequency of health service contacts for head-injury as markers of increased suicide risk.

“However, these are just one set of markers for increased suicide risk – many others are relevant including prior suicide attempt, family history of suicide, alcohol and substance abuse.  To get the complete picture of suicide risk a diverse combination of individual, relationship, community, and societal factors have to be taken into account.

“A unique approach by the authors of this study, which distinguishes it from previous research in the field, is that they adjusted for key confounders which might have provided an alternative explanation for the apparent association between head-injury and suicide.  These included pre-existing mental health problems, self-harm behaviours and fractures not involving the skull.

“There is no over-speculation, but the main limitation is that the study is based on health service encounters (outpatient, emergency department or hospitalisation) for head injury, with days in treatment used as a marker of severity.  This means of course that people who experience repetitive head injuries from contact sports like boxing and rugby, were only included if they presented to a health service with an injury.  Nevertheless the study is based on individuals aged 10 years or over, so it would seem likely that young people head-injured during a contact sport at school or college would have been assessed and their head injury recorded, even if relatively ‘mild’.  The study also did not factor in the different treatments for head-injury, and it is possible that the different treatments (rather than the head injury itself) is what affects suicidality later down the line.”

Prof Huw Williams, Associate Professor of Clinical Neuropsychology, University of Exeter, said:

“This is a tremendously important study. Traumatic Brain Injury (TBI) is a leading cause of death and disability. Maybe even greater than we knew. And it is a strong study. It has a massive population (that of Denmark over many years) and has controls for the various confounders one would need for a study like this – like pre-head-injury mental health status and so on. The measure of Traumatic Brain Injury is ‘gold standard’ in its time – based on hospital registers.

“We have known for a long time that TBI may be a strong risk factor for suicidality. With TBI making people poor at remembering and planning, and being stuck in lives of chaos and no good prospects – work and family wise. TBI also makes people impulsive and often leads to depression and anxiety. So the breeding ground in the mind for self-harm. We have – routinely – asked health and social care professionals to ask people who seem ‘at risk’ of problems (mental health, drugs, alcohol misuse & self-harm etc.) to ask about a history of TBI so that it can be taken account of. And we know that, even after a TBI, such disorders can be treated.

“This study found important trends. First, that all TBIs – including mild ones – are inked to increased risk of suicide. In general doubling the risk. Second that there can be greater risk with more severe injury – a ‘dosage’ effect.  Third, there is a particular risk period within the first six months of heightened risk.

“What can be done? People with TBI need services that allow for help to manage their lives when they are leaving hospital and are going into the community. It is vital to ensure mental health is noted early on and addressed. Support should be available as and when needed to bridge health and social services over a long term. Neuro-rehabilitation needs to be provided to enable people with brain injury to have the skills and, importantly, the confidence, to manage their lives.

“There has to be a proper system in place to flag who is at risk, with regular follow up,  so that we can reduce the risk of  survivors drifting away from family, friends, or work, and into a life where they feel they have no options.

“The All Party Parliamentary Group (APPG) on Traumatic Brain Injury, chaired by Rt Hon. Chris Bryant MP, has called for more to be done for survivors of TBI.  This makes it clear that better systems are needed. People can be helped to have meaningful lives. We must do more to stop the quiet suffering of survivors of this ‘silent epidemic.’”

Prof Alan Carson, Professor of Neuropsychiatry, University of Edinburgh, said:

“This study uses Danish population registries to examine the link between traumatic brain injury (of all causes) and suicide. It is well conducted and concludes there is a link (roughly doubling the rate). This finding is not new and the association between traumatic brain injury and suicide has been long reported. What this study adds, because it is much larger, is more precision around the rate and finds that the increase in risk is actually less than previously reported. There is an association between injury severity and increased risk with more severe injuries being associated with to increased risk. It must be understood that this is an association and it does not tell us that brain injury causes suicide, it just shows that a patient who has had such an injury is more likely to die by suicide. It may be that this relates to the brain injury or it may be that both brain injury and suicide share a common risk factor that predisposes to both.

“What is surprising is that the authors of the study and indeed the accompanying editorial have chosen to downplay one of the most important findings of the study in regards to this exploration of shared risk. When the study team examined pre-existing psychiatric problems (i.e. prior to the brain injury occurring) they found that the suicide rate in patients post-brain injury was very elevated 129 per 100 000 and this increased further if one looked at patients with a pre-injury history of deliberate self-harm to 320 per 100 000. By contrast the rate of suicide in patients who had suffered a traumatic brain injury but had neither pre-existing risk was actually lower than the Danish population average. The study authors try to explain this away with some complex statistics but the attempts are frankly unconvincing. What this tells us is that suicidal behaviour is predominantly driven by pre-existing psychiatric disorder. Other factors including brain injury and other medical conditions, but also such things as divorce and widowhood, are of course also relevant but it is the finding on previous psychiatric disorder that really stands out.”

* ‘Association Between Traumatic Brain Injury and Risk of Suicide’ by Madsen et al. was published in JAMA on Tuesday 14th August. 

Declared interests

Dr Simon Fleminger: None received

Dr Rina Dutta: None received

Prof Huw Williams: None received

Prof Alan Carson: “None to declare.”