A high-risk method for studying psychosocial antecedents of chronic pain: the prospective investigation of herpes zoster.

Although patients with chronic pain are often psychologically distressed, it has been difficult to determine whether this distress is an antecedent of chronic pain or whether it is caused by the experience of living with chronic pain. The aim of this investigation was to develop a method that would allow individuals who are at risk for the development of chronic pain to be studied before their pain has become chronic. Patients with acute herpes zoster were assessed with demographic, medical, pain, and psychosocial measures. Pain was assessed in follow-up interviews at 6 weeks and 3, 5, 8, and 12 months after these initial assessments. There were no significant differences between patients who developed short-term herpes zoster pain and patients who did not develop short-term pain for any of the measures at the initial assessment, except for one measure of pain intensity. Patients who developed chronic herpes zoster pain, however, had significantly greater pain intensity, higher state and trait anxiety, greater depression, lower life satisfaction, and greater disease conviction at the initial assessment than patients who did not develop chronic pain. In discriminant analyses, disease conviction, pain intensity, and state anxiety each made a unique contribution to discriminating patients who did and who did not develop chronic pain. This study demonstrates the feasibility of investigating psychosocial antecedents of the development of chronic pain by prospectively examining the longitudinal course of herpes zoster.