Suicide risk in people with chronic fatigue syndrome

The risk of dying is increased in many illnesses, but the mortality associated with chronic fatigue syndrome is relatively unexplored. In The Lancet, Emmert Roberts and colleagues1 report results from a case register study that linked the clinical details of more than 2000 people with chronic fatigue syndrome presenting to a specialist clinic (in London and the south of England) with mortality outcomes over 7 years. This is the largest study of its type so far, and used a robust case definition. The researchers noted that the overall risk of death in patients with chronic fatigue syndrome seemed no different from the risk in the general population. Cancer mortality was also similar. However, the findings for suicide deaths were striking—five people died during the 7-year period. Based on the suicide rate in the general population of England and Wales, the expected number would have been less than one death by suicide. In other words, suicide risk was increased almost seven-fold. A previous US study2 reported an increase in suicide mortality in people with fatigue symptoms, but was too small to show an increased suicide risk in those who met the criteria for chronic fatigue syndrome.

The results of the current study are potentially very important but need to be interpreted with caution. The study was quite small for an investigation of mortality (n=2147 patients of whom 17 died). This small sample meant that the stratified analyses in particular (investigation of the risk of death in sex, age, diagnostic, and deprivation subgroups) lacked statistical power. The increased suicide mortality (sex-standardised mortality ratio 6·85, 95% CI 2·22–15·98; p=0·002) was based on just a few deaths and the confidence intervals were wide. Two fewer suicide deaths would have meant that the findings were no longer significant.

The cohort itself was well defined but consisted of people who attended a national specialist centre run jointly by general medical and mental health service providers. This could mean that participants were representative of people with more severe or complex chronic fatigue syndrome, and the mortality findings might not be applicable to people with the disorder in primary care.

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Source: Kapur N, Webb R. Suicide risk in people with chronic fatigue syndrome. Lancet. 2016 Apr 16;387(10028):1596-7. doi: 10.1016/S0140-6736(16)00270-1. Epub 2016 Feb 10. http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(16)00270-1/fulltext (Full article)