This thesis is concerned with the psychosocial impact of psoriatic arthritis (PsA) - an inflammatory arthritis associated with psoriasis. Although an extensive literature exists on the nature and impact of psoriasis, little is known about the effect that psoriatic arthritis can have on an individual, and the bearing it may have on their quality of life. In order to address this gap in the literature, this study utilised a mixed methods research design, employing a qualitative study with semi-structured interviews, followed by a quantitative, cross-sectional postal survey. In the qualitative study, interviews were conducted with ten people living with psoriatic arthritis. Analysis of the data, using Interpretative Phenomenological Approach (JPA; Smith, 2003) resulted in five emerging themes; pain, functionality (including fatigue), emotions (including depression), coping and treatment experience/management. The quantitative study used a postal survey to measure the variables of interest and explore the associations between them. Survey respondents consisted of a sample (n = 313) drawn from The Psoriasis Association membership and also 44 from a hospital rheumatology clinic. AA participants completed a piloted questionnaire containing questions about their demographic characteristics and validated measures of quality of life. Analysis confirmed that the group with PsA fared less well on all measures of quality of life, than those with just psoriasis. Correlations identified highly significant relationships between most study variables, however of note were the relationships between fatigue and current pain (r = .547) and depression (r = .670). Within the Psoriasis Group correlations of interest included those between anxiety and social functioning (r = -.606) and DLQI and social functioning (r = -.546). Comparison of the correlations identified 18 that were significantly different between the groups. Of these, relationships between physical functioning, pain, fatigue and self efficacy were of particular interest, whilst in the psoriasis group the associations between self efficacy, social functioning and psychological health were noteworthy. This research provides some evidence that different psychosocial variables appear to be involved in the reductions in quality of life experienced by the two clinical populations in this study. The results suggest that in rheumatology and dermatology clinics, the routine measurement of fatigue, self efficacy and psychological health could be used to inform the prescribing of therapies, psychosocial interventions and drugs to improve emotional functioning, so impacting on health-related quality of life. Furthermore, these fmdings have highlighted the need to elucidate the symptom of fatigue in PsA and position it as an appropriate target not only for clinical management, but also psychological management. By advocating fatigue as a legitimate concern, this may offer patients the chance to discuss fatigue explicitly and obtain appropriate health advice
