A: The percentage of people are estimated to have AD/HD but are undiagnosed is estimated to be 4% of the population of the 5% estimated to have AD/HD. (Bruno C, Havard A, Gillies MB, et al. (2023). Patterns of attention deficit hyperactivity disorder medicine use in the era of new non-stimulant medicines: A population-based study among Australian children and adults (2013–2020). Australian & New Zealand Journal of Psychiatry. 2023;57(5):675-685. doi: 10.1177/00048674221114782)