Impact of Running on the Risk and Progression of Knee Osteoarthritis: A Review of Current Evidence.

Experiencing emotional pain is fundamentally adaptive and serves a crucial evolutionary function: it signals social loss, separation from attachment figures, or threats to social bonds, thereby motivating behaviors aimed at restoring proximity and maintaining social connections. In this sense, emotional pain acts as an “alarm system” that promotes survival and social cohesion. However, when emotional pain becomes chronic, overwhelming, or disproportionate to the triggering event, it can transition from an adaptive response to a maladaptive state, contributing to psychopathological conditions. The transition from an adaptive to a pathological response becomes evident in specific conditions, such as unresolved grief, separation anxiety disorders, or dysthymia-like states. In humans, psychological or emotional pain is self-reported and defined as “an unpleasant, overwhelming, and upsetting internal experience,” often manifested as distress, anxiety, and depression (). This aversive affective state is commonly associated with social separation, loss, and disruption of attachment bonds (). It also relates to grief and mourning—defined as an intense but transient emotional reaction to the permanent loss of a close bond (), as well as dysthymia—a persistent and chronic state of depression (). In non-human animals, assessing emotional pain remains challenging due to the absence of verbal self-reports. Nevertheless, animals exhibit behavioral and physiological responses indicative of aversive conditions. According to Panksepp, these responses can be interpreted through a framework of “critical anthropomorphism,” which allows for cautious inferences about affective experiences based on shared neurobiological substrates across species (, ). Thus, emotional suffering in animals—as inferred from experimental studies—encompasses states associated with fear, loneliness, boredom, frustration, helplessness, grief-like responses, depression, and pain (). Indeed, emotional and physical pain partially share neural pathways across species, involving both subcortical and cortical regions (, ). Empirical evidence has documented overlapping neural substrates in basic affective circuits across all mammalian brains and, to some extent, in birds. Within Panksepp’s seven basic emotional systems, those with negative valence, such as PANIC/GRIEF, FEAR, and RAGE, require contributions of different subcortical brain areas located subcortically, but modulated cortically (). These negative affective states involve partially shared neural circuits (). Panksepp has mentioned that, in this context, pain involves two general domains: (i) sensory-discriminative component and (ii) affective-motivational component (, ). In humans, the PANIC/GRIEF system is associated with psychological pain or pain related to social loss when individuals feel attachment loss or separation distress (, ). According to the social pain framework, physical and social pain rely on partially overlapping neural substrates (e.g., the brainstem, diencephalon, and certain cortical regions) rather than identical neurobiological pathways ().