BackgroundThere is limited evidence of the unmet needs and experiences of adults with Attention Deficit Hyperactivity Disorder (ADHD) in the published scientific literature. This study aimed to explore the experiences of adults in England with ADHD regarding access to diagnostic and treatment services, ADHD-related impairment and to compare experiences between patients diagnosed during adulthood and childhood.MethodsIn this qualitative study, 30 adults with ADHD were recruited through an ADHD charity (n = 17) and two hospital outpatient clinics for adults with ADHD in England (n = 13). Half of the participants were diagnosed with ADHD during childhood or adolescence and the remainder during adulthood. Semi-structured interviews were conducted and data was analysed using a thematic approach based on Grounded Theory principles.ResultsAnalysis revealed five core themes: ‘An uphill struggle’: the challenge of accessing services, ‘Accumulated Psychosocial Burden and the Impact of ADHD’, ‘Weighing up Costs vs. Benefits of ADHD Pharmacological Treatment’, ‘Value of Non-pharmacological Treatment’ and ‘Barriers to Treatment Adherence’. Accessing services and the challenges associated with securing a definitive diagnosis of ADHD in adulthood was an ‘uphill struggle’, often due to sceptical and negative attitudes towards ADHD by healthcare professionals. ADHD-related impairment had an overwhelmingly chaotic impact on every aspect of patients’ lives and many felt ill equipped to cope. A persistent sense of failure and missed potential from living with the impact of ADHD impairment had led to an accumulated psychosocial burden, especially among those diagnosed from late adolescence onwards. In contrast, positive adjustment was facilitated by a younger age at diagnosis. Although medication was perceived as necessary in alleviating impairment, many felt strongly that by itself, it was inadequate. Additional support in the form of psychological therapies or psycho-education was strongly desired. However, few patients had access to non-pharmacological treatment. In some, medication use was often inadequately monitored with little or no follow-up by healthcare professionals, leading to poor adherence and a sense of abandonment from the healthcare system.ConclusionThe findings suggest that the unmet needs of adults with ADHD are substantial and that there is a wide gap between policy and current practice in England.