The primary diagnostic category addressing pain in DSM-IV is simply called “pain disorder.” The diagnostic criteria for pain disorder, including its subtypes, are presented in

Table 60-1.

This category represents a departure from the way pain was conceptualized in the previous editions of this manual. DSM-II (American Psychiatric Association 1968) had no specific diagnosis pertaining to pain. Painful conditions caused by emotional factors were considered part of the “psychophysiological disorders.” DSM-III (American Psychiatric Association 1980) introduced a new diagnostic category for pain problems, “psychogenic pain disorder.” To qualify for this diagnosis, a patient needed severe and prolonged pain inconsistent with neuroantomical distribution of pain receptors or without detectable organic etiology or pathophysiological mechanism. Related organic pathology was allowed, but the pain had to be “grossly in excess” of what was expected on the basis of physical examination. Acceptable evidence that psychological factors were involved in the production of the pain included the following: 1) a temporal relationship was found between pain onset and an environmental event producing psychological conflict, 2) pain appeared to allow avoidance of some noxious event or responsibility, and 3) pain promoted emotional support or attention the individual would not have otherwise received. It is important to note that this kind of evidence never proves that psychological factors have caused a pain complaint.

Difficulties in establishing that pain was psychogenic led to changes in the chronic pain diagnostic criteria in DSM-III-R (American Psychiatric Association 1987; Stoudemire and Sandhu 1987). In DSM-III-R, the diagnosis was renamed “somatoform pain disorder,” and three major changes were made in the diagnostic criteria. The requirements for etiological psychological factors and lack of other contributing mental disorders were eliminated, and a requirement for “preoccupation with pain for at least 6 months” was added. In DSM-III-R, therefore, somatoform pain disorder became purely a diagnosis of exclusion. The diagnosis was made when medical disorders were excluded in a patient “preoccupied” with pain.

The DSM-IV Subcommittee on Pain Disorders found that, despite these changes, “somatoform pain disorder” was rarely used in research projects or clinical practice. They identified five reasons for this: 1) the meaning of “preoccupation with pain” was unclear, 2) whether pain exceeds that expected was difficult to determine, 3) the diagnosis did not apply to many patients disabled by pain associated with a medical condition, 4) the term somatoform pain disorder implied that this pain is somehow different from organic pain, and 5) acute pain of less than 6 months’ duration was excluded. They therefore proposed the DSM-IV category of pain disorder described earlier.

The DSM-IV subcommittee tried to devise a broader diagnostic grouping encompassing both acute and chronic pain problems. They wanted to have all the factors relevant to the onset or maintenance of the pain delineated and also to have a diagnostic category that does not require more training than most DSM-IV users would be expected to have. However, these two requirements may not be compatible. Chronic pain problems almost always have physical and psychosocial causes. The physical causes would be difficult to determine for DSM-IV users without medical training. However, this problem about determining causation is not limited to physical causes. No guidance is given in DSM-IV for determining when psychological factors have a major role in a pain problem. No guidance is given as to when psychological factors are considered important enough in the presence of a painful medical disorder to be coded as a separate mental disorder. It is not clear what is meant by a pain problem being “better accounted for” by a mood disorder. Given the high rates of mood and anxiety disorders among disabled chronic pain patients, many patients who seem most appropriate for the pain disorder diagnosis might be excluded. Depression and anxiety diagnoses point toward specific proven therapies, but this is not true for pain disorder. The diagnosis thus continues covertly as a diagnosis of exclusion with neither clear inclusion criteria nor clear implications for therapy. It seems that almost all patients with disabling chronic pain would qualify for a diagnosis of pain disorder. This can imply that chronic pain is itself a mental disorder, which is surely incorrect. But these problems with the pain disorder diagnosis do not mean that psychiatrists have nothing to offer patients with pain problems.