Adults With Attention Deficit Hyperactivity Disorder (ADHD) As An adult, individuals have many responsibilities and roles which require focus, attention, organisation and composure. Undiagnosed ADHD can struggle with some of these obligations. This can have a negative influence on their lives and cause low self-esteem. In the UK The NICE https://www.iampsychiatry.uk/adult-adhd-assessments-and-treatments/