To examine the relationship between somatosensory amplification and three factors of alexithymia (difficulty identifying feelings, difficulty describing feelings, and externally oriented thinking), 48 outpatients attending a Japanese psychosomatic clinic and 33 comparative outpatients completed the Somatosensory Amplification Scale (SSAS), 20-item Toronto Alexithymia Scale (TAS-20), Profile of Mood States (POMS), and other self-rating questionnaires. The scores on the SSAS and the first and second TAS-20 factors were higher (all P < 0.001) in the psychosomatic group than in the comparison group. The SSAS was positively associated (both P < 0.01) with these two TAS-20 factors, controlling for the effects of age, sex, group, and POMS tension-anxiety and depression. Somatosensory amplification appears to be associated with difficulties identifying and describing feelings, not externally oriented thinking, in Japanese patients.
Somatosensory amplification refers to the tendency to experience somatic sensation as intense, noxious, and disturbing.1 The construct of somatosensory amplification is helpful in the assessment of the perceptual style of somatization and in the conceptualization of psychosomatic illness.1 The Somatosensory Amplification Scale (SSAS) was designed and validated to measure this phenomenon.2
Alexithymia is a personality construct derived from clinical observations of patients with psychosomatic diseases, characterized by difficulty distinguishing between emotions and bodily sensations.3 The Toronto Alexithymia Scale (TAS) and its modified versions, the TAS-R and TAS-20, are among the most common questionnaires to measure this construct.4,5
Evidence has suggested that the tendency to develop functional somatic symptoms is associated with alexithymia.6., 7., 8., 9. and 10. A recent study reported that the SSAS was significantly correlated with the total TAS in the psychiatric sample.11 Some studies, however, have failed to find an association.12., 13. and 14.
One possible reason for the discrepancy of the results might be multiple aspects of alexithymia. One of the major domains of alexithymia, excessive preoccupation with external events, seems to reflect different aspects as compared with the cognitive inability to accurately perceive and report a full range of affects. A Japanese study15 indicated that the TAS-20 factor of “externally oriented thinking” was not statistically correlated with the other two TAS-20 factors of “difficulty identifying feelings” and “difficulty describing feelings.” Thus it might be crucial to separate a construct of alexithymia into its composing factors in analysis when the relationship between somatosensory amplification and alexithymia is argued.
We hypothesized that somatosensory amplification is primarily associated with difficulties in identifying and describing feelings because inappropriate coping of negative feelings like anxiety and depression is closely linked to the increases in stress responses and bodily sensations.16,17 To examine this hypothesis, both the SSAS and TAS-20 were applied to a cohort of patients attending psychosomatic and general medicine clinics in the university setting. Both scale scores were compared between the two groups, and the SSAS was predicted from the TAS-20 subscales, controlling for the effects of age, sex, and mood states.
