Novelty Seeking and Harm Avoidance in Somatic Symptom Disorder: The Mediating Role of Alexithymia

Abstract

Objective: Somatic symptom disorder (SSD) is strongly shaped by personality and emotional-processing factors. This study tested a model in which novelty seeking (NS) and harm avoidance (HA) predict SSD directly and indirectly through alexithymia. Methods and Materials: In a cross-sectional design, 252 students from Isfahan University of Medical Sciences were recruited. Participants completed Temperament and Character Inventory subscales for NS and HA, the 20-item Toronto Alexithymia Scale, and the Patient Health Questionnaire–15 as an index of SSD severity. Data were analyzed using structural equation modeling in AMOS 24. Model fit was evaluated with χ²/df, CFI, GFI, and RMSEA, and indirect effects were tested with 5000-sample bootstrapping and 95 confidence intervals. Findings: NS and HA were positively associated with both alexithymia (β = 0.31 and 0.39, p < .001) and SSD (β = 0.21 and 0.26, p < .001). Alexithymia also predicted higher SSD scores (β = 0.38, p < .001). Indirect effects from NS and HA to SSD through alexithymia were significant (β = 0.12 and 0.15, p < .001), indicating partial mediation. The model showed good fit (χ²/df = 2.18, CFI = 0.95, GFI = 0.93, RMSEA = 0.05) and explained 27 of the variance in alexithymia and 41 in SSD. Conclusion: Alexithymia partly explains how high NS and HA increase vulnerability to SSD. Assessing temperament and targeting emotional awareness and labeling in psychotherapy may help reduce somatic symptom burden in at-risk individuals. © 2025 the authors.