People with rheumatoid arthritis (RA), often associatedwith psychosocial problems and reduced quality of life, benefitfrom the guidance of trained medical social workers. Thisstudy explores the effectiveness of psychosocial treatmentin patients with RA using a structured interview to detectpsychosocial problems for 100 patients. These individualswere offered regular sessions with a medical social worker.Three types of mixed-problems were found: mixed problemsrelated to RA, mixed problems related to the life situation, andmixed problems related to a combination of RA and the lifesituation. The RA patients who reported mixed-problems attime of their diagnosis received psychosocial treatment froma medical social worker regardless of the mixed problems theyexperienced. In addition, we found that disease-related mixedproblems seemed more treatable than other problems. Socialwork in somatic healthcare seems most successful in patientswith sickness-related social and psychosocial problems.