Differences between functional versus organic low back pain patients.

There are contradictory findings about whether there are differences in personality and/or amount of emotional disturbance between patients with functional versus organic low back pain. The MMPI scores of 42 back pain patients diagnosed as "organic" were compared with the scores of 37 patients classified as "functional". The functional patients scored significantly higher than the organics on the Hs, Hy, Pd, Sc, Ma, and Si scales. The organics scored significantly higher than the functionals on the K scale. The results confirm the view that certain symptoms of emotional disturbance are more characteristic of patients who have relatively little evidence of physical findings. However, the degree of overlap between groups was high enough to suggest caution in making predictions and diagnoses about functional versus organic pain on individual patients solely on the basis of personality data.