Annual Research Review: Developmental language disorder - a hidden condition with lifelong impact.

Developmental language disorder (DLD) is one of the most common neurodevelopmental disorders. Yet, it is a hidden disorder: it can go undetected for years and may not be uncovered until academic, behavioral, and/or mental health challenges begin to surface. In this review, we survey what is currently known about DLD across the lifespan, with a particular focus on its collateral effects in childhood and adulthood. We begin with a brief discussion of terminological issues that have contributed to the confusion about and lack of awareness of DLD. We then describe the development of DLD from infancy through adulthood, the ways in which its presentation shifts over time and with transitions to new developmental tasks and contexts, and some of the significant associated challenges outside of the language domain that are often faced by people with DLD. Next, we review current scientific knowledge about the neurobiological and genetic bases of DLD. In the final section, we provide an overview of some of the current best practices for screening and assessment and approaches to intervention for children, adolescents, and adults. We conclude by reflecting on challenges and opportunities for future research and offering some recommendations for clinical practice, particularly for mental health practitioners.