Objectives
Alexithymia is characterized by a difficulty in identifying and describing one's emotions. Recent research has associated differential effects of the alexithymia facets to hypothalamic–pituitary–adrenal (HPA) axis markers during stress. This study aimed to analyze how the facets of alexithymia interact with autonomic reactivity as well as self- and observer-rated anxiety during a social stress task.
Methods
With the use of a public-speaking paradigm, skin conductance levels (SCLs) and heart rate (HR) during the defined periods of baseline, preparation, stress, and recovery were assessed in 60 volunteers (42 females, mean age 22.8) categorized as having either high (HDA) or low (LDA) degrees of alexithymia.
Results
We found smaller SCLs during preparation and speech in the HDA group. Regression analyses indicated that only the alexithymia facet “difficulty in describing feelings” (DDF) was associated with smaller electrodermal responses. In the HDA group, self- and observer-rated anxiety was higher in the HDA than in the LDA group, which was attributable to higher scores in the subscales “difficulty in identifying feelings” (DIF) and “externally oriented thinking” (EOT).
Conclusions
Our data support and specify the decoupling hypothesis of alexithymia by showing that the facets of alexithymia are differentially related to autonomic reactivity as well as self- and observer-rated anxiety during social stress.
Alexithymia is characterized by a marked difficulty in identifying, describing, and expressing one's emotions [1] and [2]. It was originally described by Sifneos [1] in patients with psychosomatic disorders and has been related to a broad range of physical and psychiatric disorders, e.g., alcoholism, drug addiction, and posttraumatic stress disorders [3]. At the present time, within both clinical and nonclinical populations, alexithymia is viewed as a continuous personality variable [4] which is usually assessed by the Toronto Alexithymia Scale [5]. This self-report questionnaire is the most widely used and well-validated assessment tool [5], [6] and [7] assessing alexithymia with three main facets: namely, difficulties in identifying feelings (DIF), difficulties in describing feelings (DDF), and externally oriented thinking or a preoccupation with the details of external events (EOT). There is growing empirical evidence that these facets probably refer to different correlates [8], [9], [10] and [11] with high intercorrelations between the DIF and DDF subscales and lower intercorrelations to the EOT subscale [7], [10] and [11].
Based on the observation that several stress-related diseases (see, e.g., Ref. [3]) are associated with high alexithymia, Martin and Pihl [12] suggested that alexithymia may act as a vulnerability factor, possibly by enhancing stress responses [10], [13] and [14], which is conceptualized in the “alexithymia–stress hypothesis.” Empirical data are yet not consistent: both enhanced and reduced stress reactivity or no differences in relationship to alexithymia were found [13], [14] and [15]. In this context, it is very interesting that a recent study by de Timary et al. [10] demonstrated that increased cortisol levels before social stress were associated with high scores in the DDF scale (difficulties in describing feelings) only. The authors suggested that their results shed new light on the “alexithymia–stress hypothesis,” which may be of importance to better understand the relationship between alexithymia and diseases by highlighting the possibility that alexithymia modulates cortisol levels, possibly by affecting the anticipatory cognitive appraisal of situations [10]. Furthermore, de Timary et al. [10] emphasized the factorial structure of the construct alexithymia, which should be addressed in further studies and could be one reason for the inconsistent empirical results observed so far.
The question remains open as to whether the three facets of alexithymia differentially interact not only with the hypothalamus–pituitary–adrenal axis (HPA) as demonstrated by de Timary et al. [10] but also with the sympathetic–adrenal–medullary (SAM) system. Psychosocial stress is widely known to induce various adaptive responses of physiologic systems with particular increasing activities in the HPA as well as in the SAM system. Schommer et al. [16] emphasize that rapid habituation of HPA responses after repeated exposure to stressful stimulation is a frequently reported characteristic of the HPA axis, while contradicting and less consistent results were documented concerning sympathetic activity. The authors presented evidence suggesting that with repeated psychosocial stress, a dissociation of HPA and SAM response patterns can be observed. This dissociation is characterized by a different temporal profile of habituation of catecholamine responses of the SAM system as compared to the HPA axis [16].
Based on empirical data, it still remains unclear whether, and how, hypothesized differential effects of alexithymia subscales on autonomic reactivity interact with experienced feelings of anxiety or observer-rated behavior associated with social performance during social stress. Therefore, we conducted a study aiming to detect the differential effects of alexithymia subscales on autonomic reactivity, experienced feelings, and observer-rated measures of social performance, using a social stress paradigm. We hypothesized that differences in the DDF scale (difficulties in describing feelings) should be related to autonomic reactivity in a social stress task. As former results using autonomic measures are not consistent and as to our knowledge no former study exists directly targeting this question, we phrased our hypothesis in an exploratory way concerning the probable direction of such an interaction. Furthermore, we wanted to clarify how the alexithymia facets interact with experienced feelings and observer-rated measures of social performance during a social stress task.
