The relationship of alexithymia to pain severity and impairment among patients with chronic myofascial pain: comparisons with self-efficacy,catastrophizing, and depression

OBJECTIVE: Alexithymia is elevated among patients with chronic pain, but the relationship of alexithymia to the severity of pain among chronic pain patients is unclear. Also, studies have rarely examined whether alexithymia is unique from other, more widely studied constructs in the chronic pain literature (i.e., self-efficacy, catastrophizing, and depression), and research has not examined how alexithymia relates to the sensory versus affective dimensions of pain. METHODS: Among 80 patients with chronic myofascial pain, we tested how alexithymia (Toronto Alexithymia Scale-20) was related to three competing constructs--self-efficacy, catastrophizing, and depression--and to the sensory and affective dimensions of pain as well as physical impairment. We then determined whether alexithymia remained correlated with pain and impairment when tested simultaneously with each of the three competing constructs. RESULTS: Analyses controlled for patients' sex, age, marital status, and duration of pain. Alexithymia was moderately correlated with less self-efficacy and greater catastrophizing, and substantially correlated with greater depression. Alexithymia was positively related to both affective pain and physical impairment, but was unrelated to sensory pain, whereas all three of the competing constructs were related to both types of pain as well as physical impairment. Regression analyses indicated that alexithymia remained a significant and independent correlate of affective pain severity while controlling for either self-efficacy or catastrophizing, but depression accounted for alexithymia's relationship with affective pain. Also, alexithymia was no longer related to physical impairment, after controlling for any of the other three constructs. CONCLUSION: Although alexithymia is not related to the sensory component of pain, it is correlated positively with the affective or unpleasantness component of pain, independent of self-efficacy or catastrophizing. The emotional regulation deficits of alexithymia may lead to depression, which appears to mediate alexithymia's relationship to affective pain. Alexithymia's relationship with physical impairment appears to be better accounted for by self-efficacy or catastrophizing.