Comorbid DSM-5 mental disorders and chronic pain: What kind of relationship? Findings from the P3 cross-sectional study

Purpose: Mental disorders and chronic pain frequently co-occur. The prevalence of this comorbidity varies widely across investigations and is certainly overestimated using screening self-reports. The main aim of this crosssectional research was to calculate prevalence rates of mental disorders in a chronic pain population during their first consultation in an Italian specialized pain clinic using the narrow diagnostic criteria of the DSM-5. Additionally, we examined the relationship between this psychiatric comorbidity and a broad range of sociodemographic and clinical parameters related to chronic pain. Procedures: 174 participants were enrolled in the Pain Therapy Service at the Parma University Hospital. They completed the Structured Clinical Interview for DSM-5 mental disorders (SCID-5) and the Brief Pain Inventory (BPI). Associations between psychiatric comorbidity and other parameters were explored using regression analyses. Main findings: 57 (32.7%) subjects with chronic pain had DSM-5 psychiatric comorbidity, particularly major depression and anxiety disorders. This comorbid psychopathology showed significant associations with BPI pain severity and interference scores, as well as with the presence of widespread chronic pain (including fibromyalgia) and the prescription of anti-neuropathic medication at entry. Notably, only a minority (n = 18; 31.6%) of these participants with current comorbid mental disorders were treated in psychiatric services. Conclusions: A large portion of chronic pain patients with comorbid psychiatric syndromes remain undiagnosed and undertreated. The presence of mental health operators in multidisciplinary chronic pain teams is justified and recommended.