Associations between mental health disorder symptoms and cardiac function among Royal Canadian Mounted police cadets during the Cadet training program

Cardiac regulation is a complex process involving interplay between neuroautonomic and neuroendocrine systems. Occupations frequently exposed to potentially psychologically traumatic events (PPTEs; e.g., fire or explosion, natural disaster, sexual assault), such as the Royal Canadian Mounted Police (RCMP), report elevated Posttraumatic Stress Injuries (PTSIs; e.g., Posttraumatic Stress Disorder [PTSD], Major Depressive Disorder [MDD], Generalized Anxiety Disorder [GAD], Social Anxiety Disorder [SAD], Alcohol Use Disorder [AUD]). Neurohormonal pathway dysfunction is associated with mental health disorder symptoms, but meaningful evaluations remain methodologically challenging, especially in high-stress occupations (e.g., police). The current study tested for associations among cardiac function and mental health disorder symptoms. Participants included RCMP cadets (n = 81; 28.4 % women) who completed self-report symptom measures at pre-training and pre-deployment of PTSD, MDD, GAD, SAD, and AUD. To test for longitudinal associations between cardiac function and mental health disorder symptoms, a series of paired-samples t-tests and bootstrapped partial correlations controlling for age and sex were conducted. The current study evidenced positive associations between changes in the myocardial performance index, the diastolic performance index, and isovolumic relaxation time comparable in magnitude to changes in MDD, GAD, and SAD symptoms (but not AUD symptoms), as well as between IVRT and PTSD symptoms, and rapid ejection time and GAD symptoms. The associations provide rationale for integrating cardiac rehabilitation exercise guidelines into occupational fitness programs as a method to mitigate the cumulative impact of occupational stressors.