Cortisol and Catecholamines in Posttraumatic Stress Disorder: an epidemiologic community study
Young EA and Breslau N;
Commented by , 25 Apr 2004
Aims of the study
- To examine the association of exposure to trauma and lifetime posttraumatic stress disorder (PTSD) with urinary cortisol and catecholamine (dopamine, norepinephrine and epinephrine) levels.
- To elucidate the role of comorbid lifetime major depressive disorder (MDD) on urinary excretion of cortisol and catecolamines in patients with PTSD.
Participants were selected from a 10-year follow-up cohort in a large-scale longitudinal community study of young adults. Three groups of subjects were selected for the present study:
- persons who had been exposed to trauma during the preceding 5 years
- other persons who met DSM-III-R criteria for PTSD in previous assessments
- persons preselected randomly from the cohort
24-hour urinary free cortisol (UFC) and catecholamine excretion levels were collected in all participants during a 32-hour stay at a sleep center. Diagnoses of PTSD and MDD were assessed with the National Institute of Mental Health Diagnostic Interval Schedule (NIMH-DIS) for DSM-III-R.
Urinary cortisol levels:
- Effects of trauma exposure and PTSD: there were no effects of trauma exposure and PTSD on urinary cortisol levels.
- Comorbidity with MDD: persons with MDD had significantly higher levels of urinary cortisol excretion than persons with or without PTSD.
Urinary catechoamine levels:
- Effects of trauma exposure and PTSD: a) persons with PTSD had significantly higher levels of all 3 urinary catecholamines than persons without PTSD and persons without exposure to trauma; b) persons with exposure to trauma without PTSD had lower catecholamine levels than persons without exposure.
- Comorbidity with MDD: persons with PTSD, with or without comorbid MDD, had significantly higher levels of all 3 urinary catecholamines than persons with MDD only or people without PTSD and MDD.
This is an important study on a difficult and quite controversial topic.The most important findings of the study are:
- trauma per se does not lead to sustained increases in either cortisol or catecholamine levels
- PTSD is associated with increased catecholamine levels, not, however, with increased or decreased cortisol levels
Major strengths of the study, in comparison with similar studies in the field, include
- the data come from a representative community sample
- the sample size is large
- the urine samples were collected in 8-hour intervals during a 32-hour stay of the participants in a sleep center
Limitations of the study include
- only two thirds of the subjects who had been randomly selected at the outstart accepted to participate in the study
- the number of participants with current PTSD was quite small
- the number of men with current or past PTSD was small
- diagnostic assessments were based exclusively on data that were gathered with a structured diagnostic interview
- diagnoses were made using DSM-III-R criteria, which differ to some degree with the criteria in DSM-IV-(TR) that have been in use for more than a decade now