Psychological status was investigated in 46 primary fibrositis (PF) patients, 32 with fibrositis occurring in association with rheumatoid arthritis (RAFIB) and in 76 control patients with rheumatoid arthritis. Groups were similar in tests of life stresses: Family Inventory of Life Events, Multidimensional Health Locus of Control, and self-motivation. Only 28% of PF and 25% of RAFIB had Minnesota Multiphasic Personality Inventory profiles classified as "normal" compared with 51-60% of controls. Both PF and RAFIB had elevated "neurotic" scales (hypochondriasis, depression, hysteria), but only PF patients had statistically significant elevations in the pychopathic deviancy, psychasthenia and paranoia scales. When the Arthritis Impact Measurement Scales were used, PF but not RAFIB patients demonstrated statistically significant elevations on the anxiety and depression scales.