The aim of this thesis was to explore the factors that aid or hinder implementation of evidence-based psychotherapy treatments. The literature review was a meta-analysis of studies which investigated the effectiveness of eLearning strategies for training in empirically supported psychotherapy treatments. Across the nine studies reviewed, moderate and small effect sizes were found for the improvement in learners’ knowledge and skills, respectively, following training via eLearning strategies, Outcome was moderated by type of comparison group. No significant differences were found between eLearning and traditional forms of instruction. The empirical study examined the survivability of DBT programmes and the factors that aid or hinder its implementation into routine healthcare settings. Survival curve analysis revealed no differences in the probability of survival between early and late adopters of the DBT model. Differences in the probability of survival were found for site of training. Programmes trained off-site from their service setting had a higher probability of survival than teams trained on-site. However, there was a statistically significant difference in the number of teams compared within each, which limits the conclusions that can be drawn from this finding. A number of barriers and aids to implementation were identified. The most strongly endorsed barriers were practitioner turnover and financing. The most frequently cited aids to implementation were quality of the DBT evidence base and practitioner skills. It is recommended that future research explores predictive models of implementation to understand what works where, and why. A concluding discussion highlights other areas for future research and theory development, as well as implications for clinical practice.