Styles of adaptation in autoimmune thyroiditis and bipolar disorder: a pilot study

Abstract 

Background: A growing body of evidence suggests that styles of adaptation, assessed with the Serial Color-Word Test (S-CWT, a 5-trials Stroop task), are able to differentiate several mental and psychosomatic disorders. Recent findings have confirmed a very high rate of cases of autoimmune thyroiditis (so called Hashimoto disease) among bipolar patients, suggesting an etio-pathogenetic relatedness between the two ailments. Based on the latter relatedness, it was hypothesized that the same styles of adaptation, which are known to differentiate bipolar and control subjects are also characteristic of patients with autoimmune thyroiditis. Methods: Three groups (autoimmune thyroiditis, fully remitted bipolar I, and nonclinical) of 40 women, matched on age and schooling, were administered the S-CWT. The following variables were considered: (a) early discontinuity (i.e. the summed nonlinear change of the first three trials), (b) late discontinuity (i.e. the summed nonlinear change of the last two trials), (c) across-trials discontinuity (i.e. the nonlinear change of the five measures of nonlinear change). Results: The thyroiditis group had (1) higher values of early discontinuity (P=0.006) and of late discontinuity (P=0.004) compared with nonclinical controls, (2) lower values of early discontinuity (P=0.005) and of across-trials discontinuity (P=0.008) compared with the bipolar group. Limitations: The study did not include men patients and lacked a quantification of affective symptoms among clinical and nonclinical participants. Conclusion: A discontinuous style of adaptation is more marked among remitted bipolar than among thyroiditis patients, and more marked among the latter ones than among nonclinical controls, thus delineating a sort of adaptive continuum.

Keywords:  Serial Color-Word Test, Styles of adaptation, Autoimmune thyroiditis, Bipolar disorder