آلکسیتیمیا ویژگی شخصیتی پایدار در بیماران مبتلا به اختلالات مصرف مواد نیست

The construct of alexithymia as a vulnerability factor for substance use disorders (SUD) is under debate, because of conflicting research results regarding alexithymia as a state or trait phenomenon. The absolute and relative stability of alexithymia were evaluated in a pre-post design as part of a randomised controlled trial, controlling for several co-variates. Assessments were done with the Toronto Alexithymia Scale (TAS-20) and the Addiction Severity Index (EuropASI) at baseline and follow-up of a 3-month trial of inpatient Cognitive Behavioural Therapy (CBT) with or without a Shared Decision Making intervention for 187 SUD patients. Paired sample t-tests and analyses of variance were performed to assess absolute stability, intraclass correlation coefficients were calculated for relative stability and multivariate linear regression models were used to evaluate the relation between co-variates and change in alexithymia. Mean level reduction of total TAS-20 and two subfactors demonstrated no absolute stability, but change in alexithymia differed for patients with low, moderate and high alexithymia scores. Relative stability of alexithymia was moderate to high for the total population, but differed according to low, moderate and high alexithymia scores. The EuropASI “psychiatry” domain, covering anxiety and depression, was related to alexithymia, but CBT-related variables were not. In conclusion, alexithymia is partly a state-dependent phenomenon, but not a stable personality trait in this SUD population.

Alexithymia refers to the difficulty in identifying and describing feelings, the inability to discriminate between feelings and physical sensations, having a limited fantasy life and the inclination to an externally oriented way of thinking (Sifneos, 1973). The Toronto Alexithymia Scale (TAS-20) is worldwide the most frequently used assessment instrument for alexithymia and includes three factors: (1) difficulty in identifying feelings (DIF), (2) difficulty in describing feelings (DDF) and (3) externally oriented thinking (EOT) (Bagby et al., 1994). A Dutch study (van Rossum et al., 2004) reported 54% of alcohol use disorder (AUD) patients to be alexithymic with a mean score of 56 on the TAS-20, a finding that is in accord with research on alcohol-related disorders in other studies (Thorberg et al., 2009). In other substance use disorder (SUD) populations alexithymia rates up to 67% have been found (Taylor et al., 1997, El Rasheed, 2001 and Dorard et al., 2008). Based on a reduction in alexithymia scores after detoxification in a homogeneous AUD population, it is suggested that alexithymia is a state-related phenomenon resulting from anxiety and depression (Haviland et al., 1988). In a comparable study with a heterogeneous SUD population (Pinard et al., 1996), however, no change in alexithymia scores was found and alexithymia appeared to be a stable trait. In a recent study in homogeneous AUD patients, the absolute and relative stability of alexithymia was evaluated during alcohol withdrawal; an absolute reduction (i.e., no absolute stability) of alexithymia scores was found (de Timary et al., 2008). The observed high relative stability over three time points, as well as the restricted influence of anxiety and depression, supported the view that alexithymia is a stable personality trait rather than a state-dependent phenomenon. The absolute decrease in alexithymia mean level score was in this study completely explained by a decrease of the DIF-factor. In the literature there is an extensive debate on the state versus trait concept of alexithymia that focuses on the concept of absolute and relative stability of alexithymia as a personality characteristic. Previous research showed that stability status may change according to the population that is studied (Pinard et al., 1996, Honkalampi et al., 2001, Luminet et al., 2001, Rufer et al., 2004, Saarijarvi et al., 2006, Luminet et al., 2007, Stingl et al., 2008 and de Timary et al., 2008). Absolute stability refers to the extent to which average personality scores or trait levels of a population change. It is assessed by mean-level differences over time. These indicate if and in which direction the population as a whole is changing (Caspi et al. 2005). A systematic review or meta-analysis on the stability of alexithymia as a personality trait does not exist, but a meta-analysis of longitudinal studies of personality traits, according to the Five-Factor Model, provided evidence for continued plasticity beyond age 30 (Roberts et al., 2006). Relative or rank-order stability indicates the extent to which the relative differences among individuals remain the same over time and is assessed by test–retest correlations (Caspi et al., 2005). From a meta-analysis of the rank–order stability of personality, also based on the Five-Factor Model, test–retest correlations were moderate in magnitude over time (Roberts and DelVecchio, 2000). There was an increase with age and a decrease with increasing intervals between the observations. Rank–order stability peaked sometime after age 50, at a level below unity, thus also indicating that personality traits continue to change throughout adulthood. Both meta-analyses (Roberts and DelVecchio, 2000 and Roberts et al., 2006) demonstrate that personality trait development is not just a phenomenon of childhood or adolescence but continues during adulthood. Alexithymia has been associated with negative treatment outcomes in different SUD populations (Loas et al., 1997, Ziolkowski et al., 1995 and Cleland et al., 2005), which could be a rationale for addressing alexithymia in treating SUD patients. However, only as a stable personality trait can alexithymia be an autonomous vulnerability factor for SUD, as has also been suggested by de Timary et al. (2008). As a state phenomenon, alexithymia is not an autonomous vulnerability factor because, as has been shown, it is highly related to anxiety and depression in different populations (Haviland et al., 1988 and Honkalampi et al., 2000). Anxiety and mood disorders both have a high co-morbidity with SUD and are predictors themselves for SUD (Compton et al., 2007 and Grant et al., 2009). The stability of alexithymia during or after treatment was investigated in several studies with conflicting results with regard to absolute stability. Most studies, however, supported the relative stability of alexithymia (Porcelli et al., 2003, Rufer et al., 2004, Micolajczak and Luminet, 2006, Rufer et al., 2006, Saarijarvi et al., 2006, Luminet et al., 2007, Spek et al., 2008 and Stingl et al., 2008). Depression was as a co-variable related to change in mean level alexithymia scores, especially in the DIF factor, but there was little or no relation to the EOT factor (Luminet et al., 2001). There has been little research into the effects of psychotherapy on alexithymia and the available results are ambiguous. Some studies reported no change (Iancu et al., 2006), whereas others found a decrease in alexithymia during treatment (Lumley et al., 2007). In all these studies, the interventions were not specifically aimed at reducing alexithymia; thus, the changes seen could have reflected a reduction in associated symptoms such as depression, anxiety or psychological stress (Stingl et al., 2008). Only a few reported studies (Beresnevaite, 2000 and Gay et al., 2008) were specifically aimed at reducing alexithymic characteristics. In one of the studies group psychotherapy was associated with a decrease in mean levels of alexithymia with a resulting favourable influence on the clinical course of patients with coronary heart disease. But the relative stability was still high 2 years after therapy (Beresnevaite, 2000). Evaluations of alexithymia in homogeneous and heterogeneous SUD (Keller et al., 1995 and Rosenblum et al., 2005) did not show a specific impact of various therapies on alexithymia scores. However, in one study (Rosenblum et al., 2005) alexithymic SUD patients profited more from a cognitive behavioural treatment (CBT) than from a motivational enhancement intervention. Given the conflicting results concerning the stability of alexithymia in detoxifying or recently detoxified homogeneous AUD and heterogeneous SUD populations (Haviland et al., 1988, Pinard et al., 1996 and de Timary et al., 2008) and the assumption that alexithymia only as a stable personality trait is a vulnerability factor for SUD, we were interested in evaluating the stability of alexithymia in a detoxified heterogeneous SUD population after an inpatient treatment intervention. If alexithymia were not a stable personality trait and therefore not a vulnerability trait for SUD, there would be no need to assess and address alexithymia in SUD patients. Because the therapy was not specifically aimed at reducing alexithymic characteristics, we hypothesised that a) a mean level reduction of alexithymia and factor scores relates to a reduction in anxiety and/or depression; b) no differences in change of mean level alexithymia scores will be observed between “low”, “moderate” and “high” alexithymic patients, when controlled for anxiety and depression; c) there is a moderate to high relative stability of alexithymia; and d) there is no difference in relative stability between “low”, “moderate” and “high” alexithymic patients. In addition if it is shown that variance in follow-up alexithymia could be better predicted by baseline alexithymia than “state” conditions, like anxiety and depression, this will support the argument for the relative stability of alexithymia.