In back pain, psychological factors are often major importance in both development and persistence of symptoms, and current conceptualizations of clinical diagnosis argues for the importance of simultaneous assessing the varied components and effects of pain. Unfortunately, we lack knowledge of the mechanisms by which they influence each case.

Therefore, the purpose of this study was to investigate the psychometric characteristics and pain behaviors in low back pain patients who are secondarily gained by their pain and to understand their psychodynamics. Pain qustionnaire which included the personal history of patients and their behavioral aspects, Symptom Checklist 90 Revision(SCL-90-R), McGill pain questionnaire, Visual Analogue Scale and pain drawing were obtained from 94 low back pain patients with secondary gain and from 79 patients without notable secondary gain, and psychometric characteristics and pain behaviors of the different two groups were then compared.

The data show that: ⸁ The pain was more progressive in patients with secondary gain than without that and the patients with secondary gain had poorer expectancy of cure. ⸂ Mean SCL-90-R t-score of patients group with secondary gain was significantly higher than that of patients group without secondary gain on Somatization(SOM), Interpersonal-Sensitivity (IS), Anxiety(ANX), Paranoid Ideation (PAR), Psychotism(PSY), Global Severity Index(GSI) and Positive Symptom Total(PST) scales, but all the scales were within normal range near to 50 and by SCL-90-R profile, somatization attitude was most prevalent. ⸃ Mean score of Visual Analogue Scale(VAS), Pain Rating Indices(PRI) on sensory, affective, evaluative dimensions and total sum of McGill pain questionnaire were significantly higher in patients group with secondary gain, and two groups showed difference in selecting pain describing words. ⸄ Frequency of nonorganic patterns of pain drawing and the number of pain symbols used were significantly higher in patients group with secondary gain. ⸅ Mean score of Visual Analogue Scale(VAS), Pain Rating Indices(PRI) on affective, evaluative dimensions of McGill pain questionnaire, and prevalence of nonorganic patterns of pain drawing were significantly higher in chronic cases.

These findings emphasize the importance of adopting a broader approach to multi faced problem of low back pain, and suggest that these tests be useful indicators of therapeutic strategy and prognostic evaluation.