ADHD across the Lifespan: Clinical Presentation and Systemic Obstacles in the Healthcare System

Attention-Deficit/Hyperactivity Disorder (ADHD) is one of the most common neurodevelopmental disorders diagnosed in childhood, with a growing recognition of its persistence into adulthood. Over the past decades, ADHD has become a focal point of research, clinical debate, and public health interest due to its significant impact on individuals’ academic, occupational, and social functioning. Despite its prevalence, ADHD remains underdiagnosed and undertreated, particularly in adult populations. This thesis on Attention-Deficit/Hyperactivity Disorder across the lifespan presents the clinical characteristics of ADHD in childhood/adolescence and how they evolve in adulthood. It outlines how the clinical presentation, diagnostic pathways, and treatment approaches evolve over time, reflecting the developmental trajectory of the disorder. While ADHD is typically identified in childhood, its manifestations and associated challenges persist and transform in adulthood. The transition into adult life brings greater complexity both theoretically, due to the broader and more subjective expression of symptoms, and practically, especially within the healthcare system. Adults with ADHD often face significant barriers to receiving an accurate diagnosis and appropriate treatment. These include limitations in the current diagnostic criteria, insufficient clinical recognition, and restricted access to specialized services. The second part of this thesis focuses on these systemic barriers, with a specific emphasis on the Italian healthcare context. By integrating recent international literature and national data, this work highlights the urgent need for increased awareness, improved diagnostic tools, and more inclusive healthcare practices. A comprehensive understanding of ADHD across the lifespan is essential to inform effective clinical practices and health policies and to promote equity and better support for individuals living with this condition.