Relationship between clinical pain complaints and pain sensitivity in patients with depression and panic disorder

There is evidence that depression and panic disorder are both associated with an increased frequency of clinical pain complaints. A change in pain sensitivity is alleged to be involved in this phenomenon. However, few studies have assessed clinical pain complaints and pain sensitivity in the same group of patients.

Thirteen patients with a major depressive disorder, 13 patients with a panic disorder (diagnoses based on the Diagnostic and Statistical Manual of Mental Disorders, fourth edition), and 13 healthy control subjects were investigated. None of the subjects were taking medications. Body maps were used to measure the number of painful sites as well as the intensity and unpleasantness of pain complaints in the previous 6 months. Furthermore, pain thresholds for pressure, cold, and heat were assessed at the forearm or hand.

Patients with depression and panic disorder had significantly more frequent, more intense, and more unpleasant pain complaints than healthy control subjects. Despite this similarity, patients with depression had significantly higher pain thresholds than patients with panic disorder in two (pressure and cold) of three stimulus modalities and significantly higher pressure pain thresholds than the healthy control subjects. There were no differences between the pain thresholds of patients with panic disorder and healthy control subjects. The correlations between clinical pain measures and pain thresholds were generally weak.

These findings suggest that the clinical pain complaints of patients with depression and panic disorder cannot simply be explained by changes in pain sensitivity.