Chronic pain severity and depression/somatization levels in TMD patients

The Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) axis II for psychosocial assessment was adopted to grade chronic pain severity and to correlate that severity with levels of depression and somatization in a population of chronic TMD patients.

A series of 111 consecutive patients who sought treatment for TMD symptoms lasting longer than 6 months were recruited and underwent assessment using the RDC/TMD axis II instrument. The frequencies of the different scores from the Graded Chronic Pain Scale (GCPS) and the Symptoms Checklist-90R Depression (SCL-DEP) and Somatization (SCL-SOM) scales in the study population were recorded. Correlation between categories of patients identified by the GCPS items and the SCL-DEP and SCL-SOM scales was assessed by means of the Spearman rank correlation test.

Severe or moderate somatization was shown by 47.7% and 26.1% of patients, and severe or moderate depression scores were recorded by 39.6% and 1.8% of the sample, respectively. GCPS scores showed that the vast majority of patients had a low disability or no disability at all, with only 5.4% of patients showing a severely limiting high disability. A significant correlation was found between SCL-SOM and GCPS scores, but not between SCL-DEP and GCPS, even if raw depression scores of patients with a high disability were greater than those of subjects with a low disability.

Within the limitations of the present investigation, the external validity of which is far from optimal and should be improved in future studies on more representative samples, the RDC/TMD axis II for psychosocial assessment has provided interesting data regarding the prevalence of the different degrees of chronic pain severity and their relation with levels of depression and somatization.