This thesis aims to explore the role which psychological and neuropsychological processes play in the sequelae of acquired brain injury (ABI), and holistic intervention possibilities. The first chapter consists of a systematic literature review and meta-analysis, examining the efficacy of using a physical exercise intervention to reduce reported symptoms of depression for people with an ABI. In total, 10 studies met the inclusion criteria and consisted of randomised controlled trials, non-randomised controlled trials and uncontrolled trials. In line with research in non-ABI populations, the current meta-analysis found a small to medium main effect of physical exercise on reducing reported symptoms of depression in people with an ABI. Data was not available to fully investigate the maintenance of this effect over time. The second chapter examines the empirical research investigating the relationship of self-awareness with executive function and depression in people with an ABI. 25 prospectively recruited participants with confirmed ABI more than 12 months prior to the beginning of the study completed questionnaires and neuropsychological tests, pertaining to self-awareness, depression and elements of executive function. Hierarchical multiple regression revealed that depression and set shifting were significant predictors of level of self-awareness following ABI. This suggests that both psychological and specific neuropsychological factors (set shifting) contribute to impaired self-awareness following ABI. The clinical implications and the limitations of both research papers are discussed. The third chapter discusses the papers referred to above in regard to theories of self-efficacy, which provides a potential psychological explanation as to why exercise appears to have a small to medium anti-depressant effect. It also explores how altered levels of self-awareness could influence the efficacy and delivery of physical exercise interventions. A reflective commentary is provided at the close of the thesis.