Biological responses to trauma and the development of intrusive memories: an analog study with the trauma film paradigm

Biol Psychol. 2014 Dec;103:135-43. doi: 10.1016/j.biopsycho.2014.08.002. Epub 2014 Aug 20.

Abstract

Evidence suggests that previous trauma reduces the cortisol response to subsequent stressors. We examined the relation of this response to intrusive memory, and the potential moderating roles of sympathetic reactions. Pre-existing trauma-related factors and the cardiac defense response were assessed before 58 healthy participants viewed a trauma film. Salivary cortisol and alpha-amylase (sAA) were collected pre-, peri- and post-film. Intrusive memories about the film were recorded for a week. Cortisol increased whereas sAA decreased after the film. Those with more recent traumatic experiences and greater subclinical PTSD symptoms had lower cortisol concentration post-film. Lower cortisol levels predicted greater vividness of intrusions. Positive correlations between cortisol and the frequency of intrusion were only present among individuals with more sympathetic activations. These findings suggest the contribution of insufficient cortisol secretion to over-consolidation of traumatic memory, and highlight the variation attributable to individual differences and different memory characteristics.

Keywords: Alpha-amylase; Cardiovascular defense response; Cortisol; Intrusions; Posttraumatic stress disorder; Trauma film.

MeSH terms

  • Adolescent
  • Adult
  • Female
  • Humans
  • Hydrocortisone / analysis*
  • Male
  • Memory / physiology*
  • Saliva / chemistry
  • Salivary alpha-Amylases / analysis
  • Stress Disorders, Post-Traumatic / physiopathology*
  • Sympathetic Nervous System / physiopathology*
  • Young Adult

Substances

  • Salivary alpha-Amylases
  • Hydrocortisone