Chronic pain and psychiatric morbidity: a comparison between patients attending specialist orthopedics clinic and multidisciplinary pain clinic.

Objective: The objective of this study was to examine the associations between chronic pain and psychiatric morbidity using interview-based assessments of psychiatric symptomatology. We compared the prevalence of common mental disorder (CMD; consistent with neurotic and somatic symptoms, fatigue, and negative affect), depression, and anxiety disorder(s), and associated factors with these psychiatric illnesses among Chinese patients with chronic pain attending specialist orthopedics clinic and multidisciplinary pain clinic.

Methods: A total of 370 patients with chronic pain were recruited from an Orthopedics Clinic (N=185) and a Pain Clinic (N=185) in Hong Kong. Psychiatric morbidity was assessed using the Revised Clinical Interview Schedule. Individual scores for neurotic symptoms and neurotic disorders (including depression and four types of anxiety disorders) were also calculated.

Results: The reported lifetime prevalence rates of CMD were 35.3% and 75.3% for the Orthopedics and Pain Clinic samples, respectively. Rates of depression and anxiety disorders in the Pain Clinic (57.1% and 23.2%, respectively) were significantly higher than those in the Orthopedics sample (20.2% and 5.9%, respectively) (all P<0.001). Pain characteristics including number of pain sites, pain duration, pain intensity, and pain interference were all significantly associated with psychiatric morbidity after controlling for sociodemographic factors. Pain duration and litigation/compensation status consistently predicted concurrent pain intensity and disability.

Conclusions: Chronic pain is associated with psychiatric morbidity. The higher rate of depression than anxiety disorder(s) among patients with chronic pain is consistent with previous studies that have found depression to be highly prevalent in chronic pain.