A mechanism-oriented approach to psychopathology: The role of Pavlovian conditioning.

The Research Domain Criteria Project suggests to base the classification of mental disorders on dimensions of observable behavior and neurobiological measures of these functions rather than on symptom-based descriptive categorical diagnoses. We suggest a mechanistic approach that focuses on the role of learning as a core mechanism that can be studied in animals and humans. We review human studies on neurobiological, psychophysiological, and behavioral correlates of Pavlovian associative learning and delineate commonalities and differences across disorders. In addition to the hedonic value, the learning phase (i.e. habituation, acquisition, extinction, extinction recall), the role of stimulus properties (i.e., cue and context), and event timing (e.g. delay and trace conditioning) were considered. We address how core behavioral and psychophysiological indicators of conditioning, such as contingency ratings and skin conductance responses or startle modulation, respectively, are altered. We also discuss plastic changes in core brain regions and the interaction of brain regions in inhibitory and excitatory circuits. We also address the translation of findings pertaining to classical conditioning and its affiliated processes into the development of new behavioral and pharmacological treatments for mental disorders, and discuss productive avenues for future studies.