Stress sensitivity and stress sensitization in psychopathology: an introduction to the special section.

The goal of this special section is to examine the mechanisms of enhanced sensitivity and sensitization to stress as they influence the etiology and pathophysiology of psychopathology. The 12 articles in the section focus on some of the most crucial and unanswered questions regarding the underlying mechanisms and functional consequences of stress sensitivity and stress sensitization in psychopathology. They address the constructs of stress sensitivity and stress sensitization using state-of-the-art, and often novel, methodologies. The special section also focuses on an important terminological distinction between two related but distinct stress mechanisms that are often conflated. Individuals who are sensitive to stress possess this characteristic as a putative trait that develops through genetically mediated transactional relations between temperamental characteristics and the early contextual environment. In contrast, individuals who are sensitized to stress become so over time through repeated exposure to external, as well as endogenous, stressors. Enhanced stress sensitivity and sensitization have been included in conceptual models of psychopathology. Yet, the specific mechanisms by which these stress processes impact the onset and course of psychiatric disorders are not fully understood. These articles focus on several mechanistic accounts of stress sensitivity and sensitization.