Stress fitness: A neuroscientific approach to building emotional resilience.

Across the globe, rates of mood and anxiety disorders have been increasing steadily, a trend accelerated by the COVID-19 pandemic. Stress triggers these disorders, precipitating initial episodes and provoking relapses. In this perspective, we argue that the stress system is not merely a threat mechanism but also an ongoing and active monitor of the environment and that resilience is not simply the lack of sensitivity to stress but an active function with an intrinsic neurobiology. Through the interplay of genetic, developmental, and experiential mechanisms, individuals evolve their own "stress-resilience algorithm" that determines their stress reactivity and the resulting adaptive or maladaptive consequences. This algorithm represents a dynamic, lifelong process that is often self-reinforcing. We underscore the importance of focusing on prevention by assessing and enhancing an individual's "stress fitness." This perspective offers a new conceptualization of the neurobiology of stress and resilience as a framework for basic and translational neuroscience research aimed at confronting the challenges of stress disorders.