Date of Degree


Document Type


Degree Name





Denise Hien

Subject Categories

Behavioral Neurobiology | Clinical Psychology


complex trauma, defense mechanisms, dissociation, posttraumatic stress disorder, skin conductance, TAT


The aim of this exploratory study was to link psychoanalytic theories of trauma and its impact on the mind with psychobiological research of how trauma lives in the body. The study has expanded on prior research (Cramer, 2003) to evidence that defense mechanisms do in fact moderate the relationship between stress and physiological response, and that there are likely individual differences in physiological response to traumatic stress. This study goes further to identify the psychological concomitants of these individual differences within an adult population exposed to potentially traumatic events (PTEs), and their proclivity for using different defense mechanisms. Defense use was measured simultaneously with autonomic reactivity during a stress-response task for adults with no onset of PTEs (n=14), early onset of PTEs (n=14), and late onset of PTEs (n=15). Findings suggest that there may be distinct, dissociative-like processes that differentiate the use of Projection and Identification for individuals who endorse early onset of PTEs.

Results: Hierarchical regression analyses revealed that symptomatic adults who had been exposed to PTEs prior to age 14 (early onset), and who tended to use Projection as their main defense (over Denial and Identification), demonstrated significantly lower physiological arousal than adults with late onset of PTEs. Those with early onset PTEs that used Identification as their main defense, evidenced higher physiological arousal. These findings support the idea that working with trauma populations warrants careful attention to patients' often variable, subjective experiences of stress, their own active/passive coping strategies, as well as baseline physiological reactivity, as potentially impacted by early exposure to PTEs. Altogether, this study further evidenced the multi-determined nature of posttraumatic response. Early exposure to PTEs may recalibrate defense use and bodily stress response systems, and thus must be viewed within a developmental psychopathology framework.

Keywords: posttraumatic stress disorder, complex trauma, skin conductance, defense mechanisms, TAT, dissociation