Background: The fact that alexithymia is associated with several medical and psychiatric disorders suggests that it may be a vulnerability factor for various diseases, possibly by enhancing stress responses. To test this "alexithymia-stress hypothesis", we measured the influence of alexithymia and alexithymia subfactors on the cortisol response to an acute stressor.
Methods: Twenty-eight male students were exposed to the Trier Social Stress Test (TSST), during which saliva samples for cortisol determination were collected.
Results: Subjects reacted to the stressor with a significant cortisol response. Subjects scoring high on alexithymia evidenced an increased basal anticipatory cortisol level but their peak cortisol and area under the curve were similar to that of low scorers. Multiple regression analyses revealed that the increased cortisol in high scorers was due to only one subfactor of alexithymia, "the difficulty in describing feelings" factor (DDF). DDF high scorers reacted with a large increase in cortisol during anticipation but not during exposure to the stress test.
Conclusion: The observation that alexithymia scores were associated with differences in cortisol levels before social stress exposure raises the possibility that alexithymia modulates cortisol levels, possibly by affecting the anticipatory cognitive appraisal of situations. This may be essentially attributed to the DDF factor. This observation sheds new light on the "alexithymia-stress hypothesis", which may be of importance to better understand the relationship between alexithymia and diseases. Further studies to address this issue should focus on the factorial structure of the construct and on the importance of anticipation.