Recognising the risk of increased suicide following TBI
medwireNews: Findings from a large registry-based study support an increased risk of suicide following traumatic brain injury (TBI).
The study, published in JAMA, included 7.4 million individuals aged 10 years and older living in Denmark between 1980 and 2014, 567,823 of whom had been diagnosed with a TBI.
During this period, the absolute suicide rate was 21 per 100,000 person–years, but for individuals with TBI the rate was almost twice as high at 41 per 100,000 person–years.
The incidence rate ratio (IRR) was 1.9 after taking into account important confounding factors such as pre-TBI psychiatric diagnosis, epilepsy, other fractures, a range of somatic comorbidity and pre-TBI deliberate self-harm, some of which have not been included in prior studies, Trine Madsen (Mental Health Centre Copenhagen, Denmark) and team note.
Lee Goldstein (Boston University School of Medicine, Massachusetts, USA) and Ramon Diaz-Arrastia (Penn Presbyterian Medical Center, Pennsylvania, Philadelphia, USA) also highlight in an accompanying editorial that the “increased suicide risk is relevant across all TBI severity levels, including the far more common mild injuries”, and stress that “[c]linicians, health care professionals, and mental health practitioners must take notice of this important information”.
Indeed, while the absolute suicide rate was highest among patients with severe TBI, at 50.8 per 100,000 person–years, giving a significant IRR of 2.38 compared with no TBI, the risk of suicide was still significantly increased for patients with mild TBI, at an IRR of 1.81 and an absolute rate of 38.6 per 100,000 person–years.
The researchers report that medical contact due to TBI had occurred prior to 10.2% of suicides. And the rate of suicide grew in line with increasing medical contact for TBI, from an absolute rate of 34.3 per 100,000 person–years among patients making one contact to 90.6 per 100,000 person–years among those making contact three or more times. The respective IRRs were a significant 1.75 and 2.59 compared with no contact for TBI.
These individuals making contact for TBI were at highest risk in the first 6 months after discharge, the team points out, when the IRR for suicide was 3.67, compared with 1.76 after 7 years, and particularly if their stay in hospital had been at least 3 days compared with 1 and if they were between the ages of 16 and 20 years at their first contact.
Goldstein and Diaz-Arrastia say these findings “point to an important clinical triad—TBI history, recent injury (especially with long hospital stays), and more numerous postinjury medical contacts for TBI—that serves as ‘red flags’ for increased suicide risk”.
The researchers also suggest that the association between TBI and suicide may be partly mediated by the development of psychiatry symptoms after TBI, finding the risk of suicide was higher among individuals who developed a psychiatric diagnosis or engaged in deliberate self-harm than those who did not.
“Suicide is preventable, but only with recognition of risk and prompt intervention”, stress the commentators. “The informative study by Madsen and colleagues contributes new evidence about an important public health problem that requires increased attention.”
By Lucy Piper
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