This study was designed to determine the psychopathological characteristics of low back pain. The subjects of this study were inpatients with mood disorder admitted to Jichi Medical University Hospital from April 1997 to March 2006. We extracted patients who complained of pain over one week from those inpatients. Extracted patients were grouped according to the region of pain. The “low back pain”group comprised patients who only complained of low back pain, and the “headache”group constituted patients who only complained of headaches. We compared the two groups regarding items on the face sheet, symptoms of depression, pain. The results of the study are summarized as follows : ① The low back pain group showed a significantly weaker educational background and more frequent blue-collar workers than the headache group. It was thought that there was some relation between low back pain, the educational background and occupation. ② The low back pain group showed significantly more complaints of pain before the onset of depression than the headache group. This may indicate that low back pain can be a risk factor of depression. Further consideration is needed. ③ The low back pain group showed a stronger tendency to complain of pain after object loss than the headache group. ④ After low back pain had been resolved, some patients committed suicide. It is important to be aware of this observation. ⑤ During the early stage of the treatment process,it is important for patients to feel that their doctor is always ready to hear about their anxieties and anger.