This thesis considers the difficulties engaging young people in local social and psychological services relevant to their needs, with a particular focus on those who are labelled as 'hard to reach'. It comprises three parts, which reflect the different elements to this issue. Part 1 is a literature review which considers a particular subgroup of those labelled 'hard to reach', young people with emerging personality disorder symptoms and diagnoses. It examines the different services that exist to target and treat this population, with a focus not on treatment models per se, but instead on the service context and organisation that guides the particular interventions. Common features of the services guiding these treatments are discussed, including where there are areas for future research to consider. Part 2 is an empirical research paper that evaluates different services existing to target young people labelled as 'hard to reach'. It considers Adolescent MentalizationBased Integrative Treatment and compares this approach to two groups; those with similar difficulties but receiving alternative outreach services, and healthy control participants. Fifty young people were involved, and they were assessed for differences in mentalization skills, attachment, empathy and therapeutic relationship. Findings from the investigation, as well as implications for research and clinical practice are discussed. Part 3 is a critical appraisal of the process of conducting this literature review and empirical paper. It discusses personal interests in this area, as well as conceptual and methodological issues and areas for future consideration.