Investigation of the Relationship Between Type D Personality and Depression, Anxiety and Somatosensory Amplification in Patients With Fibromyalgia.

Objective: This study aimed to investigate differences in depression, anxiety and somatosensory amplification between fibromyalgia (FM) patients with and without type D personality (TDP) and healthy controls and to examine the mediating role of somatosensory amplification in the relationship between TDP and FM severity. Methods: A total of 159 participants were included in the cross-sectional case-control study and divided into three groups: FM patients with TDP (n = 56, mean age = 45.93 ± 11.01), FM patients without TDP (n = 48, mean age = 49.17 ± 11.18) and healthy controls (n = 55, mean age = 46.1 ± 9.64). Participants were assessed with the Fibromyalgia Impact Questionnaire (FIQ; administered only to FM patients), TDP Scale, Beck Depression Inventory, Beck Anxiety Inventory and Somatosensory Amplification Scale. Mediation analysis was performed to determine the mediating role of somatosensory amplification. Results: FM patients with TDP had significantly higher levels of depression, anxiety and somatosensory amplification compared to both FM patients without TDP and healthy controls (p < 0.001). Correlation analyses showed strong positive associations between TDP and anxiety (r = 0.729, p < 0.001) and depression (r = 0.794, p < 0.001). Somatosensory amplification was found to have a significant mediating role in the relationship between TDP and FM severity (b = 0.084, 95% CI = 0.018-0.172, p < 0.05). Conclusion: These results highlight TDP as an important psychological risk factor associated with increased depression, anxiety, and somatosensory amplification in FM patients. The apparent mediating role of somatosensory amplification suggests that addressing this mechanism and psychological stress with targeted psychosocial interventions may improve the efficacy of FM treatment.