Post-traumatic stress disorder (PTSD) is a psychiatric diagnosis with a lifetime prevalence ranging from 2.1% to 5% (Koenen et al., 2017). It is characterized by a prolonged or delayed response to a traumatic event (or events) of a threatening or catastrophic nature. Individuals diagnosed with PTSD typically experience intrusive memories (“flashbacks”) or dreams of the traumatic event, distress when exposed to situations associated with their trauma, inability to recall elements of their trauma, and persistent psychological arousal (NIMH, 2019). However, the evidence base examining this association remains shaky, with most studies lacking generalisability due to their use of a veteran/military sample. To date, only two population-based Danish studies have looked at this association, and both indicated significantly higher rates of suicide in those diagnosed with PTSD (Gradus et al., 2010; Gradus et al., 2015).
- Whether a PTSD diagnosis predicts death by suicide
- Whether this association differed between men and women
- The potential impact of PTSD on death by suicide at the population level.
To examine whether suicide mortality rates differed depending on the presence of PTSD diagnoses, they conducted Cox proportional hazard models, where they accounted for an array of sociodemographic characteristics (e.g. natal sex and neighborhood deprivation level), parental severe mental illness, and personal psychiatric history (e.g. previous non-fatal suicide attempts). To determine the proportion of suicides in the population-at-risk and those exposed to PTSD, they also calculated the population attributable risk fractions and attributable fraction in the exposed.
From their initial cohort of 3,194,141 individuals, 3,177,706 (99.5%) with complete data were included in the final analyses, adding up to 49.2 million total person-years of follow up. The authors suggested that 0.7% of their sample was diagnosed with PTSD, with PTSD diagnoses being more common in migrants than Swedish-born individuals (1.1% vs 0.6%). Of those with PTSD, 0.9% died by suicide during follow-up, with a subsequent median time of 2.4 years to suicide after PTSD diagnosis. Death by suicide in those with PTSD was also more common in women than men. Furthermore, the number of deaths by suicide per 100,000 was also greater in those with PTSD in comparison to both the population as a whole and those without PTSD.
Sensitivity analyses also demonstrated that these findings were not impacted by the use of a broader definition of PTSD (i.e., including “acute stress reactions” and “crisis reactions, not otherwise specified”), the inclusion of “death by undetermined intent”, and the exclusion of people diagnosed with PTSD in outpatient settings between 2001-2005 (7.2% of all PTSD cases).
- Fox et al. (2020) have provided longitudinal evidence that PTSD is associated with increased suicide rates in the population
- Individuals with PTSD are twice as likely to die by suicide, when compared to people without PTSD
- Women with PTSD are at a particularly heightened risk
- However, there is a light at the end of the tunnel, as Fox et al. (2020) report that, assuming causality, “over 50% of all suicides in people with PTSD” could be prevented.
Implications for practice
Where can research go from here?
Firstly, there is a need to investigate how the nature of the trauma experienced (e.g. sexual assault vs combat trauma) affects the association between PTSD and death by suicide. As previous research has shown that there are specific traumas that predict a PTSD diagnosis in men (combat experience) vs women (rape and other sexual assault) (Frans et al. ,2015), the types of traumas experienced by women may be underpinning their relatively higher risk of suicide. Examining this could help us identify why we see gender differences in this association, as well as help highlight if specific traumas are linked to a greater risk of suicide.
Second, future research should aim to examine the effectiveness of a variety of interventions for PTSD, with a specific focus on suicide-related outcomes, as research has largely focused on symptom reduction so far.
albeit difficult due to the lack of Register data, it would be beneficial to attempt studies of this nature in other regions of the world.
These findings are also particularly concerning given the ongoing context of the COVID-19 crisis. Recent studies have demonstrated elevated rates of PTSD symptoms across an array of samples, including COVID-19 survivors (Cai et al., 2020) and frontline workers (Jonhson, Ebrahimi & Hoffart, 2020). In my work with UCL’s Trauma Group, I was involved in researching frontline workers’ experiences and views of psychosocial support. In doing so, I’ve heard harrowing stories of the reality of working on the frontlines during the COVID-19 pandemic, and how little psychological support frontline workers are receiving. Fox et al’s (2020) findings have made it even clearer to me how crucial it is that additional efforts are made to identify PTSD during and beyond these trying times. Knowing that a lot of PTSD-related suicides are preventable, it is vital that we do all we can to minimize the number of people falling through the cracks.
Fox, V., Dalman, C., Dal, H., Hollander, A.C., Kirkbride, J.B., & Pitman, A. (2020). Suicide risk in people with post-traumatic stress disorder: A cohort study of 3.1 million people in Sweden. Journal of Affective Disorders, 279, 609-616.
Bentley, K.H., Franklin, J.C., Ribeiro, J.D., Kleiman, E.M., Fox, K.R., & Nock, M.K. 2016. Anxiety and its disorders as risk factors for suicidal thoughts and behaviors: a metaanalytic review. In: In Clinical Psychology Review, Vol, 43. Elsevier Inc, pp. 30–46.
Blackmore, R., Boyle, J.A., Fazel, M., Ranasinha, S., Gray, K.M., Fiztgerald, G., Misso, M., & Gibson-Helm, M. 2020. The prevalence of mental illness in refugees and asylum seekers: A systematic review and meta-analysis. PLoS Med, 17(9): e1003337.
Cai, X., Hu, X., Ekumi, I.O., Wang, J., An, Y., Li, Z., & Yuan, B. (2020). Psychological Distress and Its Correlates Among COVID-19 Survivors During Early Convalescence Across Age Groups. The American Journal of Geriatric Psychiatry, 28(10), 1030-1039.
Frans, O., Rimmo, ¨ P.A., Åber, L., & Fredrikson, M. 2005. Trauma exposure and posttraumatic stress disorder in the general population. Acta Psychiatrica Scandinavica, 111(4), 291–290.
Gradus, J.L., Antonsen, S., Svensson, E., Lash, T.L., Resick, P.A., & Hansen, J.G., 2015. Trauma, comorbidity, and mortality following diagnoses of severe stress and adjustment disorders: a nationwide cohort study. American Journal of Epidemiology, 182(5), 451–458.
Gradus, J.L., Qin, P., Lincoln, A.K., Miller, M., Lawler, E., Sørensen, H.T., & Lash, T.L..2010. Posttraumatic stress disorder and completed suicide. American Journal of Epidemiology, 171(6), 721–727.
Johnson, S.U., Ebrahimi, O.V., & Hoffart, A. 2020. PTSD symptoms among health workers and public service providers during the COVID-19 outbreak. PLOS ONE 15(10): e0241032.
Kien, C., Sommer, I., Faustmann, A., Gibson, L., Schneider, M., Krczal, E., Jank, R., Klerings, I., Szelag, M., Kerschner, B., Brattström, P., & Fartlehner, G. 2019. Prevalence of mental disorders in young refugees and asylum seekers in European Countries: a systematic review. European Child and Adolescent Psychiatry, 28, 1295-1310.
Koenen, K.C., Ratanatharathorn, A., Ng, L., McLaughlin, K.A., Bromet, E.J., Stein, D.J., Karam, E.G., Meron Ruscio, A., Benjet, C., Scott, K., Atwoli, L., Petukhova, M., Lim, C.C.W., Aguilar-Gaxiola, S., Al-Hamzawi, A., Alonso, J., Bunting, B., Ciutan, M., De Girolamo, G., & Kessler, R.C.. 2017. Posttraumatic stress disorder in the World Mental Health Surveys. Psychological Medicine, 47(13), 2260–2274.
National Institute of Mental Health. 2019. Post-Traumatic Stress Disorder. Retrieved January 17th, 2020, fromhttps://www.nimh.nih.gov/health/topics/post-traumatic-stress-disorder-ptsd/index.shtml
Zalsman, G., Hawton, K., Wasserman, D., van Heeringen, K., Arensman, E., Sarchiapone, M., Carli, V., Hoschl, ¨ C., Barzilay, R., Balazs, J., Purebl, G., Kahn, J.P., S´ aiz, P.A., Lipsicas, C.B., Bobes, J., Cozman, D., Hegerl, U., & Zohar, J. 2016. Suicide prevention strategies revisited: 10-year systematic review. Lancet Psychiatry, 3(7), 646–659.