Research was conducted with two groups of arthritic patients: patients with Rheumatoid Arthritis (RA) and patients with Spondyloarthritis (SA). A chronic pain, non-inflammatory disease group of patients with Osteoarthritis, and a pain-free sample of normal people were used as controls. All groups were tested with a test battery, the items of which were analyzed to identify items indicating psychopathology but which were also related to disease process. The test battery comprised questions requesting demographic information, the Beck Depression Inventory (BDI), the State-Trait Anxiety Inventory (STAI), the Buss-Durkee Hostility Inventory (BDKH), Osgood's Self Concept Scale and the McGill Pain Questionnaire (MPQ). Hypotheses investigated were that: anxiety, depression and hostility were all elevated in arthritics compared with patients with other chronic painful disorders and pain-free controls; that anxiety, depression and hostility were all elevated in people with classical RA compared with patients with SA; that current level of pain enhances the levels of anxiety, depression and hostility in all subjects; that self concept as an indicator of coping skills moderates the levels of anxiety, depression and hostility. An analysis of variance procedure was used to find significant differences between groups. A scheffe test was used as a conservative procedure. Regression analyses were used to investigate the hypotheses that pain and self concept moderated anxiety, depression and hostility. The hypotheses were partially confirmed by the results. Patients with SA were significantly more anxious and all patient groups were significantly more depressed when compared with controls, however, in general patients were no more hostile when compared with pain-free controls. Pain enhanced depression and guilt but not anxiety or any of the other hostility variables. Self concept moderated anxiety, depression and hostility. Questions in tests were disease-related and resulted in the over-diagnosis of depression. The need for longitudinal research and research into coping skills was discussed.