A Phenomenological Deduction of Depression and Anxiety: Ten Corollaries from Clinical Observation

Current clinical diagnoses of depression are generally confounded by comorbid anxiety, leading to confusion about core mechanisms. This paper proposes the concept of "pure depression," defined as a low-energy state centered on anhedonia and reduced motivation, without significant anxiety-related somatic symptoms. From an evolutionary functional perspective, this paper re-derives the mechanistic relationship between depression and anxiety, and derives ten corollaries concerning symptom separation, negative feedback regulation, PTSD triggering, and personality formation.