Cortisol, Learning, Memory, and Attention in Relation to Smaller Hippocampal Volume in Police Officers with Posttraumatic Stress Disorder
Received 18 February 2005; received in revised form 14 June 2005; accepted 17 June 2005. published online 12 September 2005.
Background
A proposed explanation for memory impairments in posttraumatic stress disorder (PTSD) is stress-induced hippocampal damage due to elevated cortisol levels. We have previously reported smaller hippocampi in police officers with PTSD. In this study, we examined changes in and associations between cortisol, learning, memory, attention, and hippocampal volume in PTSD.
Methods
In a case-matched control study, 12 police officers with PTSD and 12 traumatized police officers without lifetime PTSD were examined with magnetic resonance imaging (for hippocampal volume), salivary cortisol tests, and neurocognitive assessments.
Results
Significantly smaller hippocampi and higher early morning salivary cortisol levels were found in PTSD. Subjects with PTSD performed worse on a delayed visual memory recall task at trend level, and made more perseverations and intrusions on a verbal memory task. Negative correlations were found between PTSD symptom severity and immediate recall function, and between re-experiencing symptoms and left hippocampal volume. A positive correlation was found between salivary cortisol level in early morning and right hippocampal volume; however, hippocampal volume did not correlate with memory.
Conclusions
Smaller hippocampi, higher cortisol levels, and memory impairments were associated with PTSD but were not directly correlated to one another. Memory impairments in PTSD do not seem to be a direct consequence of hippocampal size.
aDepartment of Psychiatry, Centre for Psychological Trauma, Academic Medical Centre, University of Amsterdam
bde Bascule and Department of Child and Adolescent Psychiatry, Centre for Psychological Trauma, Academic Medical Centre, University of Amsterdam
cGraduate School for Neurosciences Amsterdam, Amsterdam
dCentre for Work-Related Mental Disorders, Altrecht Institute for Mental Health Care, Utrecht, The Netherlands
Address reprint requests to Ramón J.L. Lindauer, M.A., M.D., University of Amsterdam, Academic Medical Centre, Department of Child and Adolescent Psychiatry, Tafelbergweg 25, 1105 BC Amsterdam, The Netherlands
ABSTRACT