This article responds to Abed and St John-Smith’s (BJPsych Bulletin, 49(2), 75–77, 2025) critique of Pain-Brain Theory (PBT). PBT offers an evolutionary account of suicide and psychopathology, proposing that suicide risk is managed by serial lines of evolved psychological systems. Front-line defenses are designed to prevent suicidal ideation. When these fail, last-line defenses activate to prevent suicidal ideas from progressing into lethal acts. The theory predicts these emergency measures will first emerge in adolescence, occur in the wake of psychologically painful life events, correlate with suicidal ideas but not their enactment, and modify affect and cognition in particular ways. These predictions match trans-diagnostic features of frequently comorbid conditions such as depression, addiction, and schizophrenia. PBT does not claim that psychiatric disorders are adaptations, but it points to certain common symptoms as manifestations of evolved anti-suicide systems. Abed and St John-Smith misrepresent the theory by treating mental disorders themselves as adaptations, and proceed to critique claims PBT does not make, such as deterministic causality and linearity. We argue that their misunderstanding reflects a deeper issue: psychiatry’s orthodoxy obstructs evolutionary insight by treating symptom clusters as natural kinds. PBT challenges this paradigm by focusing on evolved function, not diagnostic labels. This debate highlights the need to reorient evolutionary psychiatric theory toward integrative, functional explanations and away from disorder-by-disorder models. De-isolating psychiatry from evolutionary biology requires transcending the presumption that diagnostic categories are appropriate objects of evolutionary analysis.
