Alexithymia in fibromyalgia syndrome: associations with ongoing pain, experimental pain sensitivity and illness behavior.

OBJECTIVE: Alexithymia, a lack of emotional awareness, is common in chronic pain patients. The aim of the study was to investigate the relationship of alexithymia to ongoing pain, experimental pain sensitivity, and illness behavior in patients with chronic musculoskeletal pain.
METHODS: Sixty-eight women with fibromyalgia (age: average, 43.4 years; range, 19-72 years) completed self-report measures on alexithymia (20-Item Toronto Alexithymia Scale), ongoing pain [Visual Analogue Scale, Questionario Italiano del Dolore (QUID), Margolis], psychological distress (Center for Epidemiology Studies-Depression Scale, State-Trait Anxiety Inventory Form Y), and illness behavior (Illness Behavior Questionnaire). Psychophysical tests were performed to assess experimental pain sensitivity, including pain thresholds for mechanical (von Frey, tender point count) and thermal (heat, cold) stimuli, and cold pressor pain threshold and tolerance.
RESULTS: Alexithymia "difficulty identifying feelings" (DIF) was related to higher ratings of the affective-but not the sensory-dimensions of ongoing pain (QUID) and to a lower cold pressor pain tolerance, while alexithymia scores were independent of all pain thresholds. Multiple regression demonstrated that alexithymia DIF ceased to uniquely predict affective ongoing pain when psychological distress or illness behavior was separately controlled for. Higher alexithymia DIF scores were predictive of hypochondriacal illness behavior, over and above what was explained by psychological distress and affective pain.
CONCLUSION: Alexithymia is associated with increased affective pain and hypochondriacal illness behavior. The former relationship is better explained, and possibly mediated, by psychological distress and illness behavior. The hypothesis of a generally increased sensitivity to unpleasant stimuli in alexithymic chronic pain patients is not supported by the data.