OBJECTIVE: Symptoms of psychological distress, including anxiety and depressive 
symptoms, and illness perceptions are important in determining outcome in 
patients with rheumatic disease. We aimed to compare psychological distress in 
psoriatic arthritis (PsA) and rheumatoid arthritis (RA) and to test whether the 
association between psychological variables and health-related quality of life 
(HRQOL) was similar in the 2 forms of arthritis.
METHODS: In 83 PsA patients and 199 RA patients, we used the Patient Health 
Questionnaire 9 (PHQ-9), the Symptom Checklist-90-Revised, and the Brief Illness 
Perception Questionnaire to assess psychological variables and the World Health 
Organization Quality of Life Instrument, Short Form to assess HRQOL. We used 
hierarchical regression analysis to determine the associations between 
psychological variables and HRQOL after adjusting for demographic variables and 
disease parameters.
RESULTS: The prevalence of moderate to severe levels of depressive symptoms 
(PHQ-9 score ≥10) was 21.7% in PsA patients, 25.1% in RA patients, and 36.7% in 
those PsA patients with polyarthritis. After adjustment for severity of disease 
and pain, anxiety (β = -0.28) and concern about bodily symptoms attributed to 
the illness (β = -0.33) were independent correlates of physical HRQOL in PsA. In 
RA, depressive symptoms (β = -0.29) and concern about the consequences of the 
arthritis (β = -0.27) were independent correlates of physical HRQOL.
CONCLUSION: These findings suggest strongly that psychological factors are 
important correlates of HRQOL in PsA as well as in RA. Attention to patients' 
anxiety and their concern about numerous bodily symptoms attributed to the 
illness may enable rheumatologists to identify and manage treatable aspects of 
HRQOL in PsA.