Stimulant Use in High-Stress Occupational Environments: Countermeasure or Counterproductive?

In high-risk, 24/7 occupations, stimulants can serve as a countermeasure to acute stressors. However, chronic stimulant use may negatively impact operational readiness and health. Using cross-sectional data from 15,880 U.S. Navy personnel, we assessed relationships between job stress, sleep quantity and disturbance, and daily caffeine and nicotine use on readiness and health in the operational environment. Under operationally-relevant conditions of mid-high stress and poor sleep, use of caffeinated beverages (coffee/soda/tea), energy drinks, caffeine supplements (gum/pill), combustible tobacco (cigarette/cigar/pipe), electronic nicotine delivery systems (ENDS; e-cigarettes/vape), and smokeless nicotine (chew/snuff/patch/gum) associated with either no effects or significant decrements in functional performance capacity. Caffeinated beverages benefit physical and mental health under moderate job stress and low sleep quantity (< 5 h/day), but decrement under high stress; energy drinks and supplements were neutral or detrimental to health. Combustible tobacco benefits physical health under high sleep disturbance, but decrements mental health under low sleep quantity. ENDS use was neutral to physical health, with benefits in mental health under high sleep disturbance but decrements under low sleep quantity. Smokeless nicotine was neutral to health. Overall, under high operational stress conditions, caffeine associated with significant benefits to readiness and health in 4% of conditions vs. decrements in 68% of conditions; nicotine associated with benefits in 7% vs. decrements in 11% of conditions. These data indicate that in high-risk work environments, chronic stimulant use has limited benefits as a sustained countermeasure, and may be more counterproductive by compounding the detrimental effects of occupational stressors on operational readiness and health.