Related Experiment Videos
Neuroendocrine and psychophysiologic responses in PTSD: a symptom provocation study
I Liberzon1, J L Abelson, S B Flagel
1Psychiatry Service, Ann Arbor VAMC, Michigan, USA.
Summary
Post-traumatic stress disorder (PTSD) research shows heightened autonomic and stress hormone responses to trauma cues. However, these systems did not interact as hypothesized, suggesting individual differences in PTSD neurobiology.
Area of Science:
- Neuroscience
- Psychiatry
- Human Physiology
Background:
- Post-traumatic stress disorder (PTSD) research has primarily investigated autonomic, sympatho-adrenal, and hypothalamo-pituitary-adrenal (HPA) axis systems independently.
- The integrated functioning of these stress-response systems in PTSD remains underexplored.
Purpose of the Study:
- To examine subjective, autonomic, adrenergic, and HPA axis responses in a trauma-cue paradigm among individuals with PTSD and control groups.
- To test the hypothesis that integrated stress-response systems in PTSD would show strong intercorrelations.
Main Methods:
- Seventeen veterans with PTSD, 11 veteran controls, and 14 nonveteran controls were exposed to auditory stimuli (white noise and combat sounds).
- Measurements included subjective distress, heart rate, skin conductance, plasma catecholamines (epinephrine, norepinephrine), ACTH, and cortisol.
- Data were analyzed for group differences and interrelationships between response systems using canonical correlation analyses.
Main Results:
- Individuals with PTSD displayed elevated baseline levels of skin conductance, heart rate, plasma cortisol, and catecholamines.
- PTSD patients showed exaggerated responses in skin conductance, heart rate, plasma epinephrine, and norepinephrine to combat sounds, but not ACTH.
- No significant correlations were found between the different response systems in PTSD patients, failing to support the integrated response hypothesis.
Conclusions:
- PTSD is characterized by heightened reactivity in specific physiological systems to trauma-related cues, but not necessarily integrated multisystem responses.
- The lack of intersystem correlations suggests that individual differences or distinct pathophysiological processes may influence which neurobiological systems are affected in PTSD.