While there exists a small but growing literature on the effects of stress and mental health prevalence for emergency first responders, a paucity remains for first responder research focusing on the pathogenic effects of the stress response that incorporates both traditional psychosocial measures of stress and biological markers of stress measured by salivary endocrine levels for the stress-linked hormones cortisol and testosterone. Stress research in the social sciences has overwhelmingly evidenced the allostatic effects of cortisol and testosterone in the human and animal stress response. The cross-talk between the two hormone pathways when an individual perceives stress affects mental health and lends growing support for investigation of the dual-hormone hypothesis of cortisol and testosterone in models of psychopathology. Psychological and physiological stress variables were measured at baseline for a cohort of local emergency first responders (N=190). Traditional stress-buffering (stress-protective) psychosocial constructs of social support and resiliency were also measured. Symptoms of mood, anxiety, and trauma-related disorders, alcohol use, and sleep quality were assessed at baseline, but also, at 3-month and 6-month follow-up for each participant. Ordinary least square (OLS) linear regression was used to predict if hormone biomarkers and self-reported baseline perceived stress were associated with change in clinical symptoms at 3-month (N=158) and 6-month follow-up (N=111). No single nor dual hormone effects of cortisol or testosterone were supported within the data as diatheses for stress-linked psychopathology. High numbers of models corrected for by adjusting p values and small sample size are likely implicated in null findings. In addition, study limitations are discussed regarding calculation of prediction models using OLS regression rather than multi-level modeling regression. The addition of further refined endocrine and psychosocial stress variables is discussed for future studies. This study contributes a comprehensive literature review of the first responder stress literature and a novel investigation of the dual-hormone hypothesis within a population of first responders.