Attention deficit hyperactivity disorder (ADHD) is characterized by symptoms such as inattention, hyperactivity, and impulsivity, with a significant impact on a person’s overall health and well-being. The impact of ADHD on healthcare costs is limited.The aim of this study is to examine the extent to which a diagnosis of ADHD affects health expenditure.The study group contained all Maccabi HMO patients aged 18 and over who have a diagnosis of ADHD. The control group included patients aged 18 and over without ADHD in a ratio of 1:3 matched by propensity score . We compared ADHD vs non-ADHD medical costs for each calendar year between 2018–2023. Group comparisons of medians are reported using the non-parametric Mann–Whitney U test in unadjusted analyses. Annual healthcare costs were analysed using a generalized linear model with a Tweedie distribution and a log link function, appropriate for right-skewed cost data with non-negative values.The study included 32,159 individuals diagnosed with ADHD and 96,632 non-ADHD controls. Between 2018 and 2023, individuals with ADHD demonstrated persistently higher annual healthcare costs compared with non-ADHD controls, with significant differences observed across all calendar years and cost categories. Category-specific analyses showed that physicians cost as well as hospitalization cost, contributed most to this difference, while medications cost showed smaller but increasing differences over time. Generalized linear model showed that male gender was associated with lower expected costs compared with females; smokers had 20% higher expected costs than non-smokers and age was positively associated with cost. Socioeconomic status was inversely related to cost.For our research we used a relevant data rich source. Nevertheless, other factors like ADHD heterogenicity, treatment complexity, and nonmedical treatment can affect the results. ADHD profiles and treatment adherence pattern can also affect cost data.Our finding show that healthcare costs of patients diagnosed with ADHD is higher than patients not diagnosed with ADHD in many categories of healthcare costs. There is more research needed to identify what are the main cost amplifiers.