Recent Trends in Medication Treatment of Attention Deficit Hyperactivity Disorder (ADHD)

Abstract

Objective:

In recent years, ADHD diagnosis rates and stimulant use have increased, particularly among adults. This has occurred in the context of increased telehealth use and shortages in stimulant medications. To better understand changes in ADHD medication use and inform policy governing the prescribing of these medications, this study compared stimulant and non-stimulant fills for 2019 and 2023.

Methods:

This study uses national all-payer prescription claims data for 2019 (before the onset of the COVID-19 pandemic) and 2023 to calculate stimulant and non-stimulant ADHD medication fill rates overall and by patient age and prescriber specialty.

Results:

Total ADHD medication fills increased 23.8% from 2019 to 2023; stimulants accounted for most fills (91.4% in 2019; 88.9% in 2023). While the number of stimulant fills rose 20.4% from 2019 to 2023, the number of non-stimulant fills increased at three times that rate (60.1%). Both stimulant and non-stimulant fills increased among adults, with stimulant fills decreasing 6.5% among children 0–18. Nurse practitioners and physician assistants (NP/PAs) together were responsible for one in three ADHD medication fills in 2023; non-stimulants were used more commonly among NPs/PAs and psychiatrists relative to other specialties.

Conclusions:

From 2019 to 2023, there was a substantial rise in the number of ADHD medication fills. While stimulants still dominated, there was a dramatic increase in use of non-stimulants even though non-stimulants are not first choice ADHD medication treatment. This increase was likely due at least in part to stimulant shortages that continue to limit access to ADHD pharmacotherapy nationally.

Attention deficit hyperactivity disorder (ADHD) is a prevalent condition characterized by inattention, hyperactivity, and/or impulsivity; it is associated with lower educational attainment and higher rates of accidental injury, depression, anxiety, substance use disorder, and all-cause mortality.^1–3 Pharmacotherapy – either stimulants or non-stimulant medications (guanfacine, clonidine, atomoxetine, and viloxazine) – is efficacious for treating ADHD.^{4, 5} Meta-analyses that examine the relative efficacy of stimulant versus non-stimulant medications indicate that while both are efficacious in ADHD care, stimulants are considered first choice medications because they are relatively more efficacious in treating ADHD compared to non-stimulants;⁶ however, some patients do not tolerate stimulants due to side effects. Additionally, stimulant prescribing is subject to additional regulation because stimulants are Schedule II controlled substances due to increased risk for physical and psychological dependence.

In recent years, ADHD diagnosis rates and stimulant use have increased, particularly among females and young adults.^7–10 Some are concerned about the potential for overdiagnosis or misuse of stimulant medications associated with these increases, while others point to long-term underdiagnosis and undertreatment of ADHD,^{11, 12} particularly among some groups. While growth in stimulant use predates the COVID-19 Public Health Emergency (PHE), recent increases in ADHD diagnosis and fill rates have occurred in the context of a shift toward telemedicine that began during the COVID-19 pandemic and was facilitated by regulatory changes relaxing requirements for an in-person evaluation before prescribing controlled substances. Some worry that telehealth prescribing could lead to greater stimulant misuse and diversion, and there are concerns about prescribing by fully virtual telehealth companies after Department of Justice investigations of some firms for possible Controlled Substances Act violations.¹³ Increased diagnosis and fill rates are also occurring alongside nationwide stimulant shortages first reported in 2022 and continuing.¹⁴

To better understand changes in ADHD medication use and inform public policy and clinical practice, we compared stimulant and non-stimulant fills for 2019 and 2023, overall and by patient age and prescriber specialty.

Methods

We use all-payer, aggregate national data on the number of stimulant and non-stimulant ADHD medication fills in 2019 and 2023 from IQVIA. (List of medications is available in online supplement.) These data cover 95% of prescriptions filled in U.S. retail and mail order pharmacies. Fills are classified by prescriber’s specialty (primary care physician (PCP), psychiatrist, pediatrician, nurse practitioner/physician’s assistant (NP/PA), other); patient age (children 0–18, adults 19–30, and adults 31+); and, for stimulants, whether it is considered short-acting vs. long-acting (short-acting stimulants are generally viewed as having greater potential for misuse than long-acting).^15–19 We report changes in the number and share of fills. The need for institutional review board approval was waived due to the use of secondary, non-identifiable data.

Results

The total number of ADHD medications dispensed increased 23.8%, from 72,849,441 in 2019 to 90,183,437 in 2023 (Figure 1 and table in online supplement). Stimulants accounted for most dispensed ADHD medications – 91.4% in 2019 and 88.9% in 2023. However, the percentage increase in non-stimulant fills was much larger than the percentage increase in stimulant fills (60.1% vs. 20.4%, respectively).

Figure 1: Percentage Change in Number of ADHD Medication Fills, 2019 vs 2023.

Source: Authors’ analysis of prescription drug data from IQVIA. The total number of medication fills for all ages combined for each category of drugs (stimulants, non-stimulants, and all ADHD medications) appears below the category name. The number of fills by age group and year appears in the online supplement (Appendix Table 1).

For stimulants, the increase in fills was largest among adults age 31+, jumping 44.1% from 28,981,489 to 41,766,266 and accounting for 94.1% of the entire increase in stimulants dispensed from 2019 to 2023. In contrast, stimulant fills increased 17.9% (from 13,320,120 to 15,704,620) among adults 19–30 and decreased 6.5% (from 24,311,233 to 22,728,122) among children. In 2023, just over one in four stimulant fills (28.3%) were used by children.

Non-stimulants were used most by children, who accounted for 56.7% (n=5,661,533) of non-stimulant fills in 2023 (down from 73.2%, n=4,561,857, in 2019). However, there has been a dramatic increase in the number of non-stimulants dispensed to adults, increasing 138.8% for adults 19–30 and 172.9% for adults 31+, versus 24.1% for children (Figure 2). The percentage of dispensed ADHD medications that were for non-stimulants almost doubled from 5.2% to 9.9% for adults 19–30 and from 3.2% to 5.8% for adults 31+, while increasing only from 15.8% to 19.9% for children (Figure 2).

Figure 2: Percentage of ADHD Medication Fills that are for Non-Stimulant (vs. Stimulant) Medications, by Patient Age, 2019 vs. 2023.

Source: Authors’ analysis of prescription drug data from IQVIA. The total number of ADHD medication fills by age group and year appears below each set of bars.

NP/PAs played a much larger role in ADHD prescribing in 2023 than 2019. For stimulants, NP/PAs accounted for 32.1% of dispensed medications in 2023 (n=25,736,417) vs. 20.7% in 2019 (n=13,760,401) (Figure 3). For non-stimulants, the increase in the share written by NP/PAs was even larger, jumping from 27.7% (n=1,730,308) to 42.7% (n=4,266,546).

Figure 3: Percentage of Stimulant and Non-Stimulant Fills by Prescriber Type, 2019 vs. 2023.

Source: Authors’ analysis of prescription drug data from IQVIA. Chi-square tests comparing the results over time for stimulants and non-stimulants were both significant (p≤0.001). The total number of fills for 2019 and 2023 for stimulants (on the left) and non-stimulants (on the right) appear at the bottom of the figure.

NP/PAs and psychiatrists prescribed non-stimulants (relative to stimulants) more often than other specialties. For example, in 2023, 28.2% of NP/PA (2,092,567 of 7,427,299) and 26.9% of psychiatrist (1,633,742 of 6,072,067) ADHD fills for children were for non-stimulants, versus just 12.1% for pediatricians (1,406,368 of 11,674,453) (Figure 4). PCPs rarely prescribed non-stimulants.

Figure 4: Percentage of ADHD Medication Fills that are for Non-Stimulant (vs. Stimulant) Medications, by Prescriber Type and Patient Age, 2023.

Source: Authors’ analysis of prescription drug data from IQVIA. The total number of ADHD medication fills for each group above is provided in the online supplement (Appendix Table 2).

Despite changes in the number of stimulants dispensed and characteristics of patients and prescribers using them, the share of stimulant prescriptions that were short-acting remained constant (n=38,725,854 or 58.1% in 2019 vs. n=47,110,668 or 58.7% in 2023) (Figure 5).

Figure 5: Percentage of Stimulant Fills for Short-Acting (vs. Long-Acting) Medications, 2019 vs. 2023.

Source: Authors’ analysis of prescription drug data from IQVIA.

Discussion

From 2019 to 2023, there was a substantial rise in the number of ADHD medication fills. While stimulants still dominated, there was a dramatic increase in use of non-stimulants even though non-stimulants are not first choice ADHD medication treatment. This increase was likely due at least in part to stimulant shortages that continue to limit access to ADHD pharmacotherapy nationally.

ADHD medication increases were largest among adults. Increases among both younger and older adults were accompanied by a drop in stimulants dispensed to children. In prior literature, increases in identification of ADHD and stimulant prescribing in adults have been documented well before the pandemic’s onset.^{20, 21} There is some evidence that this trend represents a narrowing of the gender gap in identification of ADHD among women who were not identified as youth, during a period when ADHD was less often noted in girls relative to boys due to their commonly having more inattentive presentations instead of hyperactivity.²¹ Despite this, as noted above, the magnitude of increased stimulant use among adults has raised concerns about possible misdiagnosis and/or overprescribing given the lack of professional guidelines for the diagnosis and treatment of ADHD in adults (the American Professional Society of ADHD and Related Disorders has convened a committee to develop guidance but a report has not yet been released). Undertreatment of ADHD also remains a concern.^{7, 22–24}

Our findings on the increase in stimulant and non-stimulant fills, particularly among adult populations, are consistent with those of Chai et al.,⁹ who used IQVIA data for the period April 2018 through March 2022 to compare changes in incident use of several types of behavioral health medications (antidepressants, benzodiazepines, buprenorphine, stimulants, and non-stimulant ADHD medications). During this earlier period, they found rates of incident use were relatively stable for antidepressants, benzodiazepines, and buprenorphine, but ADHD medication use increased notably. Our study extended this prior work by assessing whether trends in the number of fills continued through calendar year 2023 (21 months later) and examining the shift in the mix of stimulant and non-stimulant fills in more detail--for different patient populations and by different types of prescribers. Our study further adds to the literature by examining whether prescription fill patterns have changed in terms of short-versus long-acting stimulants — the latter of which are thought to have a higher abuse potential.^15–19

The substantial rise in ADHD prescribing by NP/PAs is consistent with their increased role in behavioral health treatment in recent years.²⁵ While NP/PAs are responsible for a large share of the increase in stimulant prescribing since 2019, they prescribe non-stimulants more often than most other specialties. A limitation of our data is that we were unable to distinguish whether NP/PAs were specialty-trained in mental health (e.g., Psychiatry/Mental Health Nurse Practitioners (PMHNPs). Thus, the observation that non-stimulant prescribing among non-psychiatrists was highest among the NP/PAs may reflect this provider category being a mix of prescribers who are and are not specialty trained in mental health.

While the U.S. Drug Enforcement Administration (DEA) adjusted aggregate production quotas for selected stimulant medications over the past two years in response to ongoing reports of shortages,¹⁴ these adjustments have not offset the increase in stimulant demand over this period. We are unable to assess the extent to which the shift toward non-stimulants is due to difficulty accessing stimulants in the context of shortages. Given that clinical trial evidence suggests that non-stimulants are not as effective for some patients,^{6, 26} some people using non-stimulants because of access difficulties might choose to switch to stimulants in that case. We are also unable to determine the extent to which some patients may have abandoned stimulant prescriptions without filling any ADHD medication prescription because of the inability to access stimulants, suggesting that demand for ADHD medications may be higher than dispensing data suggest.

While our data do not allow us to assess the extent to which stimulant fills resulted in misuse, self-reported data from other sources suggest a recent decline in rates of non-medical use of stimulants. For example, according to the National Survey on Drug Use and Health, self-reported stimulant misuse dropped from 2.0% in 2015 to 1.5% in 2022 for those 12 and older.²⁷ In addition, national surveys of adolescents and young adults show recent decreases in non-medical stimulant use.^{28, 29}

Importantly, the increase in stimulant fills over the past five years was not accompanied by an increase in the share of short-acting stimulants. Such an increase might have raised concerns about the possibility of an increase in misuse, given that short-acting medications are generally viewed as having greater potential for abuse than long-acting stimulants.^15–18

It is important to note several limitations of our analysis. Using only pharmacy data, which lacks information on the diagnoses for which a medication is prescribed by a clinician, we were unable to determine whether dispensed prescriptions were used by someone with an ADHD diagnosis or whether the prescription fills we observe resulted in misuse or diversion. Bupropion has a limited evidence-base for off-label use in ADHD treatment,³⁰ but is not included in the IQVIA ADHD medication categories and therefore is not included in our analyses. With data from only two years (2019 and 2023), we were unable to assess year-to-year trends or whether one of these years might be an outlier. However, Chai et al⁹ found a continued upward trend in stimulant prescribing from 2018–2022, suggesting that our results are not outliers. As noted above, we were unable to determine whether the NP/PAs were specialty-trained in mental health or the setting in which they practice (e.g., pediatrics, internal medicine). Also as noted above, we were unable to assess the extent to which the shift toward non-stimulants is due to difficulty accessing stimulants in the context of the shortages. Finally, these data on filled prescriptions do not allow us to determine whether short- and long-acting stimulants are used together or instead prescribed as monotherapy.

Conclusions

ADHD medication prescribing has risen dramatically in recent years. These changes are greater for adults compared to children. While ADHD medication fills rose dramatically, they did so for non-stimulant as well as stimulant ADHD medications; also, there was not an increase in the prescribing of short-acting stimulants, which are thought to have more abuse/misuse potential compared to long-acting stimulants. While we are unable to observe diversion or misuse in these data, our study adds to the developing literature about ADHD medication prescribing in the wake of both a marked increase in telemedicine in ADHD care and a shortage in stimulant availability and can inform ongoing policy discussions on this concern.

Highlights:

• There was a dramatic increase in the number of ADHD medication fills from 2019 to 2023; the rise was most pronounced among non-stimulants (60.1% increase vs. 20.4% for stimulants).

• The increase in stimulant fills among adults 31 and older (44.1%) accounted for 94.1% of the entire increase in stimulant fills from 2019 to 2023. In contrast, stimulant fills increased 17.9% among adults 19–30 and decreased 6.5% among children.

• Nurse practitioners and physician assistants play a much larger role in ADHD medication prescribing in 2023 than 2019, accounting for one in three fills in 2023 (vs. one in five fills in 2019).