It has long been recognized that depressive traits are commonly associated with muscle contraction headache. Our studies of patients with chronic pain afflicting various body parts led to the delineation of a psycho-biological profile consisting of typical depressive features, in addition to a set of characteristic clinical, premorbid and historical features. We term this syndrome the pain-prone disorder and consider it a variant of depressive disease. This study compared psychobiological profiles of patients whose pain was localized to the head with that of patients whose pain was localized to single and multiple areas elsewhere. Of a total 627 chronic pain patients referred to the Henry Ford Hospital Pain Clinic after no somatic cause for their pain was substantiated, 32 patients complained of headaches only, and 53 complained of pain with single localization elsewhere; we randomly selected an additional 53 patients who complained of pain in multiple locations. The headache patients differed from all other pain patients in only three respects: their pain was less continuous; there was greater denial of emotional problems, though a larger number reported suicidal gestures. All groups were likewise depressed. The results support the concept of chronic pain as a variant of depressive disease, regardless of location.