Assessment and diagnosis of post-traumatic stress disorders (PTSDs) for medico-legal and other clinical purposes: DSM-5-TR PTSD, ICD-11 PTSD and ICD-11 complex PTSD

SUMMARY Post-traumatic stress disorder (PTSD) is a complex, heterogeneous mental health problem that can be challenging to identify, assess, understand, diagnose and treat. This article provides an overview and critique of key topics, literature and principles to inform comprehensive and meticulous assessment of PTSDs. Although expert witnesses are the target audience, this article will have relevance for identifying, assessing, understanding and diagnosing PTSDs in all clinical contexts. A range of topics relevant to assessment are discussed, including: the complex relationship between trauma and PTSDs; DSM-5-TR PTSD and ICD-11 PTSD and complex PTSD diagnoses and the similarities and differences between them; the clinical presentation of PTSDs; psychological models of PTSDs; how to approach assessment and differential diagnosis; the impact of PTSD on neuropsychological abilities and functioning (disability); causation, reliability and assessing PTSDs when this is being considered as a legal defence; evidence-based interventions (medication, psychological therapy, when is the ‘right time’ for therapy, contraindications); and prognosis (if untreated, how long therapy/change takes). Given ongoing debate, the article proposes that trauma exposure is best defined in future iterations of the DSM and ICD as exposure to one or more psychologically threatening or horrific experiences that are overwhelming.