This chapter provides accurate information and practical guidance and support. It explores the diagnostic criteria and living experience of personality disorder, the prevalence and impact of personality disorder, the development and causes or aetiology, assessment and diagnosis, and treatment and supervision. Personality disorders are generally perceived to be relatively common and complicated conditions with a heterogeneous mixture of symptoms which pervasively influence the way people think and feel about themselves and the way in which they interact with others. They may behave in ways that challenge the accepted norms of society. Relational recovery is being evaluated in the context of the whole system including in comparison to evidenced-based psychological therapies in primary and secondary mental health care. The role of the relational recovery team is to provide specialist training, consultation, support and supervision to the frontline workforce in inpatient and community settings, as well as providing clinical care.