The volume provides differential diagnostic guidelines in relation to other persistent mental disorders such as autism spectrum, ADHD, schizotypal disorder, bipolar disorders, and Complex PTSD. The wide array of contributors integrate a range of evidence-based psychotherapy approaches including Dialectical Behaviour Therapy (DBT), Mentalization Based Therapy (MBT), Transference-Focused Therapy (TFP), Cognitive Behaviour Therapy (CBT), Intensive Short-Term Dynamic Psychotherapy (ISTDP), Metacognitive Interpersonal Therapy (MIT), Good Psychiatric Management (GPM), Nidotherapy, and Schema Therapy to describe the available instruments and measures, including how to use different sources of diagnostic information.