- Tomoko Tetsunaga: Department of Orthopaedic Surgery, Okayama University Hospital, 2-5-1 Shikata-cho, Kitaku, Okayama, Okayama, 700-8558, Japan. kwdtmk1201@yahoo.co.jp
BACKGROUND: Depression can exacerbate symptoms of chronic pain and worsen disability. The symptoms of lumbar disease may be particularly sensitive to psychological state, but statistical associations between low back pain (LBP) severity and mental health status have not been established.
METHODS: Of the 151 patients with LBP, 122 completed questionnaires probing depressive symptoms, LBP severity, and degree of disability. In addition to completing self-report questionnaires, patients provided demographic and clinical information. A self-rating depression scale (SDS) was used to screen for depression. Pain and disability were assessed by the visual analog scale (VAS) and the Roland-Morris disability questionnaire (RDQ), respectively. Overall clinical severity was assessed using the Japanese Orthopaedic Association (JOA) score. Kendall's tau correlation coefficients were calculated to examine the relationships among these variables.
RESULTS: Ninety-four patients (77 %) were in a depressive state as indicated by SDS score ≥40, including mild depression group (47 patients, SDS score from 40 to 49) and depression group (47 patients, SDS score ≥50). There were only 28 patients in the no depression group (SDS score ≤39). There was no significant difference in both age and pain duration among the three groups. The mean VAS score in the depression group (70 ± 19 mm) was higher than both no depression (41 ± 24 mm) and mild depression groups (52 ± 21 mm). The mean JOA score in the no depression group (14 ± 5.0 points) was higher than both mild depression (12 ± 4.0 points) and depression groups (10 ± 6.0 points). The mean RDQ in the depression group (15.1 ± 6.0 points) was higher than both no depression (6.4 ± 5.0 points) and mild depression groups (10.9 ± 5.4 points). Factors significantly correlated with SDS score included VAS, JOA score, and RDQ score. In contrast, SDS did not correlate with patient age or pain duration.
CONCLUSIONS: The majority of chronic LBP patients examined were in a depressed state and the severity of depression correlated with pain severity, degree of self-rated disability, and clinical severity.