There are significant costs associated with ADHD. However, the focus of previous studies has typically included the increased healthcare attendances and medication, with the data originating from insurance databases (Doshi et al, 2012). There are less data surrounding total societal costs (education, justice and productivity), with only a few studies taking into account comorbidities within cost estimates (Daley et al, 2019). Therefore, the aim of this study was to investigate the social and economic costs of ADHD, using Australia as an example. The authors aimed to examine both financial and non-financial costs that are associated with ADHD across the lifespan.
A literature review was conducted to calculate ADHD prevalence and to estimate financial and non-financial costs related to ADHD in Australia for the 2018 to 2019 financial year. A bottom-up approach* was used to estimate cost across most domains and required accurate estimates of ADHD prevalence. Whereas a top-down approach† was utilised where data were available (e.g. pharmaceutical costs). ADHD prevalence in children, adolescents and adults was calculated separately due to changes in prevalence across the lifespan. Mortality associated with ADHD was extrapolated from a Norwegian study due to lack of Australian data (Dalsgaard et al, 2015). Health system cost estimations of hospitalisations, visits to general practitioners and specialists, medications and health research expenditure due to ADHD were calculated. A top-down approach was utilised for estimation of medication costs and health research expenditure. There was also calculation of productivity cost estimations of workforce participation, temporary absenteeism, presenteeism or reduced productivity at work, premature mortality and value of informal care due to ADHD. Other cost estimations of government services (education and justice system), loss of future income due to premature mortality and dead weight losses or reduced economic efficiency due to ADHD were calculated. Loss of well-being cost estimations of reduced quality of life, impaired functioning and premature death due to ADHD were evaluated. One-way sensitivity analysis was conducted to aid in characterisation and explanation of uncertainty surrounding expected costs of ADHD in Australia. Costs were converted from Australian dollar to US dollar.
Prevalence of ADHD
Overall prevalence of ADHD was estimated to be (3.2%; 620,900 [4.9%] males; 193,600 [1.5%] females) across all ages. In 2019, ADHD contributed to an estimated 64 premature deaths; ~85% of the 64 deaths were male (aged 15–29 years).
Financial costs of ADHD
The estimated total health system costs associated with ADHD in 2019 were $321.1 million ($394 per individual with ADHD). The majority of the health system costs (80%) were incurred within hospitals ($128 million) or in out-of-hospital care ($128.5 million). Pharmaceutical costs were estimated to be 20% of total health system costs ($63.4 million). Estimated annual ADHD research allocated funding in 2019 was 0.3% of total health system costs ($1.1 million). Furthermore, total productivity costs were estimated to be $6 billion ($7424 per individual with ADHD) in 2019. Estimated cost of absenteeism was $1.7 billion ($2087 per individual with ADHD), presenteeism (working while sick) was $1.9 billion ($2389 per individual with ADHD) and reduced employment was $2.16 billion ($2654 per individual with ADHD). The total other cost estimations were calculated to be $1.08 billion in 2019; educational costs were $74.1 million, crime costs to the justice system were $215 million and deadweight losses from government expenditure of services, programmes and reduced taxation revenue were $790.9 million due to ADHD.
Non-financial costs of ADHD
The overall loss of well-being estimations were calculated to be 36,653 years of life lost due to disability and 4236 years of life lost due to premature death associated with ADHD. Therefore, disability adjusted life years due to ADHD were estimated to be 40,890, as cost of loss of well-being was $5.31 billion in 2019. Disability adjusted life years were estimated to be higher in males than females and peaked at 10–14 years, which reflects the greater prevalence of ADHD in males and in children and adolescents. Overall, the total financial costs due to ADHD were estimated to be $7.45 billion; combined with the well-being loss the total costs are $12.76 billion. It was estimated that of this total cost, $10.9 billion was associated with adult ADHD.
Sensitivity analysis highlighted that the most sensitive to change was the total cost of ADHD in the productivity impacts. The total cost of ADHD was estimated to be $8.4 billion to $17.44 billion in 2019.
There were some limitations to the study. Firstly, although ADHD has a similar prevalence globally, the understanding of the impact of ADHD comes from Westernised societies and there is relatively little information on the impact of ADHD on other societies (Polanczyk et al, 2007). Secondly, other studies have shown that ADHD prevalence increases when using the Diagnostic and Statistical Manual (DSM-5™) compared with DSM-IV criteria (Matte et al, 2015; Vande Voort et al, 2014). Prevalence could affect cost estimates in this study with costs increasing to $17.4 billion when using the average of the range. Finally, this study was focused on Australia, although the findings could be generalised across similarly developed countries, it is unclear how well the findings could be applied to low- and middle-income countries.
In summary, the study highlighted that ADHD imposes significant costs on economy and well-being and can have lifelong impacts on individuals. This finding can place significant pressure on society and its institutions. The authors stated that there is a need to raise public awareness of the socioeconomic burden of ADHD and to educate key stakeholders to drive investment into research in order to reduce the burden and lifelong impact of ADHD.
Read more about the social and economic cost impact of ADHD here
*Bottom-up approach involved estimating the number of cases incurring each cost item and multiplying the number of cases by the average cost per item
†Top-down approach accesses the total costs of a programme element using availability data (e.g. accessing existing data to estimate the costs of ADHD medications)
Daley D, Jacobsen RH, Sørensen A, et al. The economic burden of adult attention deficit hyperactivity disorder: a sibling comparison cost analysis. Eur Psychiatry 2019; 61: 41-48.
Dalsgaard S, Østergaard SD, Leckman JF, et al. Mortality in children, adolescents, and adults with attention deficit hyperactivity disorder: a nationwide cohort study. Lancet 2015; 385: 2190-2196.
Doshi JA, Hodgkins P, Kahle J, et al. Economic impact of childhood and adult Attention-Deficit/Hyperactivity Disorder in the United States. J Am Acad Child Adolesc Psychiatry 2012 51: 990-1002.
Matte B, Anselmi L, Salum GA, et al. ADHD in DSM-5: a field trial in a large, representative sample of 18- to 19-year-old adults. Psychol Med 2015; 45: 361-373.
Polanczyk G, de Lima MS, Horta BL, et al. The Worldwide Prevalence of ADHD: a systematic review and metaregression analysis. Am J Psychiatry 2007; 164: 942-948.
Sciberras E, Streatfeild J, Ceccato T, et al. Social and economic costs of attention-deficit/hyperactivity disorder across the lifespan. J Atten Disord 2020; Epub ahead of print.
Vande Voort JL, He JP, Jameson ND, et al. Impact of the DSM-5 attention-deficit/hyperactivity disorder age-of-onset criterion in the US adolescent population. J Am Acad Child Adolesc Psychiatry 2014; 53: 736-744.