Neuroticism, alexithymia, negative affect and positive affect as predictors of medically unexplained symptoms in primary care

Background: Somatization has been defined in a number of ways. Despite their differences, these definitions have one element in common, namely the presence of somatic symptoms that cannot be explained (adequately) by organic findings. Objective: The primary objectives of the dissertation were to gain a better insight into the concept of somatization, and to study (prospectively) the relationship between neuroticism and alexithymia, two personality traits that have been shown to be related to somatization, the affective state dimensions positive and negative affect (or psychological distress) and medically unexplained symptoms. Method: A selective review was conducted regarding conceptual and methodological issues related to somatization. A total number of 318 patients, presenting to their primary care physician with medically unexplained symptoms, participated in the prospective study. Both at baseline and at 6-month follow-up a number of measures were filled out with respect to somatization, neuroticism, alexithymia, negative and positive affect, anxiety and depression. Results: The concept of somatization was clarified, thereby making use of the distinction between presenting and functional somatization. The personality traits neuroticism and alexithymia were found to have an indirect influence on symptom reports. Both the cross-sectional and follow-up data pointed to the importance of positive and negative affect as determinants of (changes in) number of symptoms (over time). Negative affect, together with the alexithymia dimension measuring difficulty identifying feelings, predicted symptom persistence. Conclusions: The theoretical as well as therapeutic implications of the present paper may give an impetus to new research in the domain of somatization.