For over a decade now researchers and clinical psychologists have been promoting a transdiagnostic (or 'unified') approach to depression and anxiety within the general population. Advocates of the transdiagnostic approach suggest that there are common underlying factors across anxiety and depression, and that these disorders may be part of the same fundamental emotional syndrome. This viewpoint may be highly relevant to the traumatic brain injured (TBI) population, as psychological distress post-TBI often presents as a range (or syndrome) of neurological-emotional reactions, rarely fitting neatly into a diagnostic category. Therefore, a transdiagnostic approach may offer an enhanced understanding of the factors which underlie depression and anxiety following TBI. This review aimed to examine existing empirical support concerning the rationale for a transdiagnostic conceptualisation of depression and anxiety post-TBI. A broad review of the TBI literature was conducted that encompassed studies investigating factors related to emotional adjustment and treatment studies targeting emotional adjustment. Three main lines of preliminary support for a transdiagnostic approach were identified, including; (1) high comorbidity between depression and anxiety symptoms, (2) observed treatment response for non-targeted aspects of emotional function, and (3) some common underlying neuro-cognitive, psychological and social factors found to be related to both depression and anxiety post-TBI. However, despite this preliminary support the review highlighted that research is yet to adopt a transdiagnostic approach, and specifically examine common factors contributing to depression and anxiety following TBI. Such research has the potential to guide the development of more unified and efficacious psychotherapeutic interventions.