Alexithymia and somatisation: quantitative review of the literature.

OBJECTIVE: To present a quantitative review of the empirical literature on somatisation and alexithymia.
METHODS: Medline and PsycLIT searches for relevant studies were conducted. Meta-analytical techniques were applied to quantify the strength of the associations that were found.
RESULTS: A small to moderate relationship was found between general alexithymia and somatic symptom reporting. The alexithymia dimension measuring difficulty in identifying feelings showed the strongest association with symptom reports. The alexithymia dimension measuring externally oriented thinking was virtually unrelated to somatic symptom reports. Compared to healthy control populations, subjects suffering from a somatoform condition were significantly more alexithymic, with effect sizes ranging from moderate to large. The studies comparing somatoform to medical or psychiatric conditions yielded inconclusive results.
CONCLUSIONS: By means of quantitative procedures, an association between general alexithymia and somatic symptom reporting was established. Due to the use of questionnaires that can only check for symptoms, not whether these symptoms are medically explained or not, it is however not possible to draw conclusions on somatisation properly defined. The inconsistent results found when comparing somatoform conditions to medical and psychiatric controls may be attributed to confounding variables. In future studies, these variables should be statistically controlled to establish a more consistent pattern of associations between somatoform conditions and alexithymia. It is, however, equally feasible that this inconsistency reflects the nonspecific character of the association between alexithymia and somatisation. The presence of only one prospective study does not allow to draw conclusions on alexithymia as a predisposing factor for somatisation.