Fig. 3.

Illustrative example of chronic stress-induced allostatic triage from the central executive network (CEN) and goal-directed and executive functions to the salience network (SN) and vigilance, fear, habitual, compulsive, and stimulus-response behaviors. We propose that this process results from stress-induced reductions in biological metabolic efficiency (i.e., the efficiency of metabolism itself) and allostatic metabolic efficiency (i.e., the efficiency of allostatic regulation), and is regulated by affective states, which represent internal models of metabolic efficiency, a process that we call affective prioritization. Critically, allostatic triage is exacerbated by the affective dysregulation caused by chronic stress. Arrows represent activation and blunted lines indicate inhibition. Black indicates the normal effects of stress and white indicates the effects of allostatic triage. The background color indicates stress intensity with yellow/orange indicating mild or acute stress, light red indicating intense or chronic stress, and dark red indicting stress-induced disease pathogenesis. The shift from light red back to yellow indicates recovery, which may be impaired after chronic stress. The bidirectional white arrows between biological and allostatic metabolic efficiency indicate the mutual dependence of both processes. The white arrow and blunted inhibition symbol from reduced allostatic metabolic efficiency to increased vigilance, fear behaviors, habits, etc, and increased goal directed behaviors and executive control indicate allostatic triage from expensive executive functions that optimize long-term outcomes to less costly behaviors that ensure short-term survival. The white arrows and inhibition symbols from negative affect to vigilance and fear behaviors, and goal-directed behaviors, respectively, during “impaired recovery”, indicates that the process of rebound enhancement of the CEN after stress is impaired after chronic stress-induced allostatic dysregulation, driving psychiatric symptoms. Importantly, the CEN and SN are represented here as illustrative examples, but we propose that allostatic triage occurs among all functional brain networks, depending on their predicted outcomes and metabolic costs. Figure created on BioRender.com.