Pain-patient MMPI subgroups: the psychological dimensions of pain

Two-hundred-forty male pain patients were given the MMPI and an extensive pain history questionnaire. A hierarchical clustering procedure was used, and three distinct profiles emerged. One profile was essentially "normal," while a second profile revealed the "hypochondriasis" configuration, and a third was highly elevated on scales which reflect a "psychopathological" type of profile. A discriminant analysis yielded functions correctly classifying over 90% of the subjects in each group. Although the three groups did not significantly differ on age, education, income, IQ, assertiveness, type of pain, or years of pain duration, they did differ on the pain history questions relating to pain severity and pain impact on their lives. The psychopathological group reported significantly more distress than the hypochondriasis group, and the hypochondriasis group reported significantly more distress than the normal group. The implications for pain treatment are discussed.