Alexithymia in individuals with chronic pain and its relation to pain intensity, physical interference, depression, and anxiety: a systematic review and meta-analysis.

Numerous studies have examined how alexithymia (difficulty identifying and describing one's emotions and a preference for externally oriented thinking) relates to chronic pain and associated disability. We conducted a systematic review and meta-analysis to summarize individual studies that either assessed alexithymia in individuals with chronic pain vs controls or related alexithymia to pain intensity, physical interference, depression, and anxiety. We searched MEDLINE, Embase, and PsycINFO from inception through June 2017; 77 studies met the criteria (valid assessment of alexithymia in adults or children with any chronic pain condition) and were included in analyses (n = 8019 individuals with chronic pain). Primary analyses indicated that chronic pain samples had significantly higher mean alexithymia scores compared with nonclinical (d = 0.81) and clinical nonpain (d = 0.55) controls. In chronic pain samples, alexithymia was significantly positively associated with pain intensity (d = 0.20), physical interference (d = 0.17), depression (d = 0.46), and anxiety (d = 0.43). Secondary meta-analyses of 14 studies that conducted partial correlations that controlled for negative affect-related measures revealed that alexithymia was no longer significantly related to pain intensity or interference. Meta-analysis findings demonstrated that alexithymia is elevated in individuals with chronic pain and related to greater pain intensity and physical interference, although the latter relationships may be accounted for by negative affect. Critical future work is needed that examines alexithymia assessed using non-self-report measures, develops a person-centered perspective on this construct, and identifies how alexithymia is relevant to the assessment and treatment of individuals with chronic pain.