ADHD medications’ real-world benefits diminish as prescription rate rises

Attention-deficit/hyperactivity disorder (ADHD) medications are associated with reduced risks of several serious real-world outcomes, but the magnitude of these associations has decreased alongside rising prescription rates, a nationwide study has shown.

The prescription rate of ADHD medications has risen substantially in many countries over the last two decades. “This is the first study to examine how these changes influence the associations between ADHD medication and serious real-world outcomes over time,” wrote the researchers. [JAMA Psychiatry 2025;doi:10.1001/jamapsychiatry.2025.1281]

Associations remain significant

Using data from the Swedish National Registers, the researchers conducted a population-based study that included 247,420 individuals who used ADHD medications between 2006 and 2020. During this period, ADHD medication use increased nearly 5-fold (from 0.6 to 2.8 percent) in children and >10-fold in adults (from 0.1 to 1.3 percent).

The researchers examined real-world outcomes across three time periods, including 2006–2010 (median age, 16 years; female, 33.9 percent), 2011–2015 (median age, 17 years; female, 38.2 percent), and 2016–2020 (median age, 18 years; female, 41.6 percent).

ADHD medication use was associated with significantly lower rates of all studied outcomes, including self-harm (incidence rate ratio [IRR], 0.77–0.81), unintentional injury (IRR, 0.87–0.93), traffic crashes (IRR, 0.71–0.87), and crime (IRR, 0.73–0.84), across all time points.

“We have now shown that these associations remain even when prescription rates have increased substantially,” noted the researchers.

Decreased magnitude of associations

However, the magnitude of associations between ADHD medication use and lower risks of unintentional injury, traffic crashes, and crime (p_trend <0.01 for all) appears to have become attenuated over time, coinciding with an increase in prescription rate during the same period.

Changes in age and sex distribution of individuals receiving ADHD medications did not fully explain the weakening trend for unintentional injury and traffic crashes, whereas the trend for crime was no longer statistically significant.

Changing patient population over time

“The declining strength of the associations could be attributed to the expansion of prescriptions to a broader group of individuals,” noted the researchers. With increases in the number of ADHD diagnoses and medication prescriptions, it is likely that patients being diagnosed and treated for ADHD today display milder symptoms or impairments compared with those diagnosed and treated 15 years ago.

The findings underscore the importance of continuously evaluating medication use in different patient populations and regularly updating treatment guidelines to better reflect the changing patient population. “[Our work] provides an important foundation for future research, but more high-quality research is needed to inform these updates,” remarked the researchers.