Understanding common obstacles and solutions to deliver effective psychological treatment

There is substantial evidence suggesting that psychological therapies are largely effective for the treatment of mental health difficulties. However, the evidence-base has also demonstrated that some individuals do not improve after psychotherapy and others actually deteriorate. Therefore, there is a pressing need to understand how to improve outcomes in psychotherapy. One approach to this is understanding the factors that predict good treatment response, so that therapists can make treatment decisions based on empirically based prognostic indicators. There is a well-documented literature highlighting social support as a relevant factor for mental health difficulties, especially for individuals with depression. However there remains considerable uncertainty about the extent to which social support may be associated with depression treatment outcomes. Part I of this thesis is a systematic review and meta-analysis exploring associations between pre-treatment social support and psychotherapy outcomes for adults with depression. The results of 25 studies, including 7576 patients, were identified and synthesised and, of these, 12 studies were meta-analysed. Studies included randomised controlled trials and observational cohort studies. The quality of studies was assessed, ranging from low to high quality; however, the study quality did not influence the results. Higher levels of social support before psychotherapy were found to be significantly associated with lower depression severity following psychotherapy, especially in studies that used Cognitive Behavioural Therapy (CBT). This suggests that assessments of social support and early interventions aimed at increasing social support may be beneficial for improving depression outcomes, especially in CBT.