Poor Health related quality of life (HRQoL) is associated with worse health outcomes for COPD patients' and is therefore an important outcome in COPD clinical care and research. The variance in COPD patients HRQoL is not well accounted for by measures of lung function. Psychosocial factors, such as depression and anxiety have been found to be closely associated with poor HRQoL. Panic disorder is also a highly prevalent comorbidity with COPD and is associated with worse patient reported outcomes but there has been little research conducted on the impact of panic on HRQoL in COPD. The aims of this PhD study were firstly to identify the psychosocial predictors of HRQoL in COPD. Secondly to test whether panic predicts HRQoL in COPD and thirdly to identify whether panic was a better predictor of HRQoL in COPD than depression.A systematic review was conducted to review the existing evidence for psychosocial predictors of HRQoL in COPD. Eight longitudinal cohort studies were identified and the results were pooled using random effects meta-analysis. There was a large and significant positive correlation between depression and prospective HRQoL at 12 months, and a moderate but significant correlation between anxiety and prospective HRQoL at 12 months. No studies were identified which had looked at the impact of panic disorder on HRQoL in COPD.A longitudinal cohort study was conducted across 10 general practices in Manchester, UK. 188 participants completed 12 month follow-up (81%). Self-report data were collected on socio-demographics, psychosocial factors, general and respiratory HRQoL and healthcare use. Data on the severity of COPD were collected from general practice notes. In simple linear regression analyses panic significantly predicted physical and emotional respiratory specific HRQoL at 12 months. However, this effect did not remain in multivariable models which included depression. Structural equation models (SEM) were used to explore and quantify the relationships between depression, anxiety, and panic, and respiratory HRQoL at 12 months. The results showed that for both physical and emotional respiratory HRQoL there was a high and statistically significant covariance between depression and anxiety, depression and panic, and anxiety and panic at baseline. However, only depression significantly predicted physical HRQoL at 12 months. Depression was also found to mediate the relationship between anxiety and respiratory HRQoL but not between panic and respiratory HRQoL. This study has shown that depression is the greatest psychosocial predictor of respiratory HRQoL in COPD. Future work should focus on identifying the effect of panic on short term outcomes in COPD such as, healthcare use and medication use, using larger samples which would allow the specification of more complex models and using a clinical interview for the identification of panic.