ADHD medication: A Horizon Scan

ADHD is one of the most common neurological disorders and greatly impacts the health-related quality of life of affected individuals and their families. ADHD is definitively underdiagnosed and the treatment potential is most probably not fully realized - despite effective medications. The resulting health economic costs of ADHD are substantial and it remains to be seen whether new drug innovations will make a future contribution to reducing the disease burden.


Attention/hyperactivity disorder (ADHD) is a neuropsychiatric impairment of childhood and adulthood and is manifested by various symptoms such as decreased attention span and reduced impulse control. The diagnosis of ADHD is challenging but clearly defined according to international diagnostic criteria (e.g. ICD10 / WHO, DSM5). The prevalence in the population is relatively well investigated and is reported to be 5% in school-aged children and about 2.5% in adults respectively (Ref. 1). This means that in Switzerland there are about 86'000 children and adolescents and 172'000 adults - a total of about 258'000 affected persons living with the diagnosis of ADHD. The health-related quality of life of ADHD sufferers is lower than that of healthy people and often associated with comorbidities.


ADHD has a large impact on the health economic budget and produces significant societal costs. Direct medical costs (assessment and treatment), social costs (especially school and education) and productivity losses add up to 10'000 Euros per patient per year or more (Ref. 2) - with medication costs contributing only a small part (in Switzerland about CHF 570 per patient per year). In purely theoretical terms, the 258,000 Swiss ADHD patients thus cause socially relevant costs amounting to CHF 2.5 billion.


Approved active substances: low treatment rates are surprising

Usually the treatment of ADHD is approached with medication and / or behavioral therapy. Extrapolated data from Switzerland show that the drug treatment rate of under-aged ADHD patients is about 21% - for adults it is in the range of 26% (Ref. 3). These treatment rates indicate that ADHD is underdiagnosed and undertreated. It is estimated that the diagnosis rate is approximately 50%.


Various drugs are approved for the treatment of ADHD. In Switzerland, methylphenidate, dexmethylphenidate, lisdexamphetamine, atomoxetine, and guanfacine have been introduced into the market and are available in various galenic formulations. Methylphenidate is the most widely used ADHD drug, accounting for over 70% of all swiss prescriptions. Lisdexamphetamine is the second most used agent, accounting for approximately 12% of all prescriptions, and dexmethylphenidate is the third most used agent, accounting for approximately 9% of all prescriptions (Ref. 3). All substances have a significantly better effect than placebo. The active substances are comparable to each other in their effect sizes. Only methylphenidate seems to be significantly superior to atomoxetine (Ref. 4).


New innovative pharmaceuticals for ADHD therapy available soon?

Additional agents are in clinical research & development. Our March 2021 search resulted in 77 projects being developed in the ADHD indication area. Our analysis revealed that four Phase III and 6 PII projects are of significant potential interest. Among the PIII projects, two molecules have attracted our particular interest and we are eager to see how the innovation will establish itself in the highly competitive ADHD environment.


In summary, ADHD is a common, underdiagnosed, and undertreated disorder that causes relevant distress to affected individuals and their families. The health economic costs are considerable and it is therefore encouraging that effective medications are available and new agents will expand the treatment arsenal in the near future.


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References:

1) Rae T et al. 2015, Dirks H et al. 2017

2) Le HH et al. 2017

3) Helsana Arzneimittelreport 2020

4) Cortese S et al. 2018