It has been our experience that treatment outcome is usually better in chronic headache patients as compared to those patients with the chronic intractable benign pain syndrome. Of primary interest to us were possible differences in personality characteristics which may be considered positive discriminators between these pain groups and, potentially, a pre-treatment screen for positive outcome.
The Million Clinical Multiaxial Inventory (MCMI) was the psychological assessment device used to determine specific psychological and personality characteristics in our subject population. This 175 item self-administered questionnaire was designed to replace the MMPI. It was normed on psychiatric samples and is compatible with DSM-III diagnoses. An innovative and desirable feature of the MCMI is the use of “base rates” in scale construction to maximize true positives and reduce false positives.
Twenty-five headache (HA) and twenty-six non-headache chronic benign pain patients (CBPS) were evaluated medically and administered the MCMI. Twenty psychology graduate students served as controls.
“Base rate” scores above 60 were indicative of a statistically significant presence of psychopathology on each of the 20 MCMI scales. The non-headache pain group was found to show a number of significantly elevated scales (P<.01): passive-aggressive personality; anxiety; dysthymia; and alcohol abuse. Both the headache group and the CBPS group showed significant elevation (P<.01) on eleven of the twenty MCMI scales. The student control group had elevations on the histrionic and narcissistic personality scales which did not achieve statistical significance.
These results, using the MCMI, reinforce previous observations of greater psychopathology among pain patients, but appear to differentiate between chronic headache and non-headache pain patients. The significance of this discrimination and possible inferences regarding both treatment outcome and its prediction are discussed.