Comparison of MMPI profiles in medically and psychologically based insomnias.

The MMPI performance of two sub-groups of chronic insomniac patients was compared to determine if patients with psychologically based insomnia (Group 1) differed from those with medically based insomnia (Group 2). This was done to establish whether etiology of insomnia had an impact on the psychological picture. We postulated that Group 1 would show a higher overall incidence of psychopathology, particularly on scales suggesting internalization of distress. Surprisingly, the results revealed no significant differences between the groups with respect to these questions. When the two diagnostic groups were combined, the sample as a whole was characterized by a high overall prevalence of psychopathology. As many as 79.3% of the MMPI records contained one or more clinical scales in the pathological range. Depression was a prominent feature. Our findings emphasize the importance of not assuming that a patient with an organically-based insomnia (e.g. due to sleep apnea, etc.) is free of psychological disturbance. This, in turn, underscores the need for a psychological evaluation as a routine part of the diagnostic work-up of all insomniac patients, regardless of the etiology of their disorder.