Multimorbidity and suicidality among military veterans: a scoping review

Veterans face elevated risks of suicidality, including suicidal ideation, attempts, and death by suicide. Multimorbidity, the co-occurrence of at least two physical or mental health conditions, has been associated with suicidality. This scoping review aimed to map and synthesise the existing literature on the relationship between multimorbidity and suicidality among veterans from the Five Eyes group, an intelligence alliance between Australia, Canada, New Zealand, the United Kingdom, and the United States.

The review involved a comprehensive search of academic databases (PubMed, Scopus, Embase, APA PsychInfo, PTSD Pubs) and grey literature. Data extraction focused on study characteristics, types of multimorbidities, and suicidality outcomes.

A total of 42 studies were included. The majority of studies focussed on U.S. veterans (n = 39) and ex-serving veterans (a person who has served at least one day and has since discharged) (n = 37). Studies generally focused on psychiatric-psychiatric multimorbidities (n = 21) or psychiatric-physical multimorbidities (n = 21). No studies focussed exclusively on physical-physical multimorbidities. Studies of psychiatric-only multimorbidities concentrated on PTSD and depression, while studies that included physical multimorbidities concentrated on traumatic brain injury or comorbidity indices.

The experience of multimorbidities appears to confer additional risks of suicidality to veterans. However, multimorbidities have been unevenly examined to date with key conditions of relevance to veterans being overlooked. There is also limited diversity in the study populations examined and relatively little evidence on the role of mediating psychosocial factors. Further research in these areas is important to informing and improving prevention activities, and clinical and service responses.