stressors include heat, psychological stress (which can be extraordinarily intense in combat operations), and sleep loss. Because soldiers are typically exposed to multistressor environments, the optimal treatment for any individual stressor might also have beneficial effects that generalize across other stressors. However, there is no reason to believe that if a treatment is effective in one environment it will also work in others.
Cold, heat, and hypoxia have different physiological effects. In the case of heat and cold, some of the effects, at least on the peripheral nervous system, are in opposition (Murphy and Redmond, 1975). Therefore, it may be likely that treatments for the adverse peripheral consequences of exposure to various stressors will not have common positive effects across stressors. In fact, treatments that have beneficial effects in one environment could even have adverse effects in other environments. It is also possible however, that enhancement of certain critical metabolic or physiological functions such as energy utilization or cardiovascular function would generalize across different stressors. Appropriate nutritional supplements might, in theory, be good candidates for producing beneficial effects in various environments and in situations in which multistressor exposure occurs. In addition, if there are common elements in the response of the central nervous system (CNS) to different types of stressors, modulation of these mechanisms could be a generic treatment for the adverse effects of stress. Treatments that are less stressor-specific might have significant advantages over strategies that are targeted at specific metabolic functions associated with individual stressors.
If it can be determined what underlying brain mechanisms are responsible for the adverse CNS response to stress, assuming there are some, it may be possible to find practical interventions—nutritional or other—to treat some of the adverse symptoms associated with the CNS components of the stress response. At the U.S. Army Research Institute of Environmental Medicine (USARIEM), a comprehensive program has been initiated to evaluate the neurochemical and behavioral effects of various stressors on brain function. One of the key objectives of this program is to specify which neurochemical changes are responsible for the adverse behavioral effects of stressors. With this basic information, researchers at USARIEM hope to determine how to treat adverse behavioral effects of stress appropriately by preventing or mitigating the underlying neurochemical deficits with nutrient and drug treatment. To date, two environmental stressors have been studied in some detail: cold and high altitude. Researchers hope to extend the research to various other stressors. In addition, two neurochemical systems have been studied that are believed to be intimately involved either in the response of the organism to stress (specifically the catecholaminergic system), or in critical behavioral functions such as learning and memory (specifically the cholinergic system).