Predicting the Intensity of Pain in Patients With Chronic Pain Based on Alexithymia: The Mediating Role of the Behavioral Inhibition System

Objectives This study aimed to predict the intensity of pain based on the amount of alexithymia in patients with chronic pain, and in this relationship, the behavioral inhibition system has a mediating role. Methods The present study has a correlational design and carried out with a structural equation modeling approach. The statistical population comprised all 20-60 years old patients with chronic pain who had referred to Mahan Clinic and the physical medicine and rehabilitation clinic of Arman in Tehran, from spring to autumn of 2017. Of them, 488 patients who had experienced the musculoskeletal pain for at least 3 months, were chosen purposefully and asked to respond the Toronto Alexithymia Scale (TAS-20), the inhibition/activation system scale, and Numeric Rating Scale (NRS). The analysis was done in SmartPLS. Results The intensity of pain had a positive relationship with inhibition system (P<0.001) and fight/flight system (P<0.05). Alexithymia had the positive a relationship with inhibition system (P<0.001). Alexithymia (t=6.34, beta=0.29), inhibition system (t=3.77, beta=0.17), and fight/ flight system (t=4.26, beta=0.18) could explain the variance of the pain intensity. Alexithymia could explain the activity of inhibition system (t=8.03, beta=0.30) and the behavioral activation system (t=2.83, beta=-0.14). Conclusion The relationship between alexithymia and the intensity of pain was not a simple direct relationship, but the inhibition system with its avoidance behavior output could affect this relationship.