ADHD in Teenagers: Age of Stimulant Medication Initiation, Duration May Impact Drug Misuse

Earlier age at initiation of stimulant medication for attention-deficit/hyperactivity disorder (ADHD) and a longer duration of use are associated with less misuse of stimulants during adolescence, according to investigators of a study published in The Journal of Child Psychology and Psychiatry.

In the United States, ADHD has been diagnosed in about 10% of children and adolescents (4-17 years of age) 75% of whom have received medication therapy. Children with ADHD are at increased risk of initiating substance use and developing substance use disorders. In the current study, investigators aimed to evaluate whether earlier age of stimulant medication initiation (≤9 years old) and a longer duration of prescription stimulant therapy (≥6 years) for ADHD is associated with higher or lower rates of misuse of prescription stimulants, methamphetamine, or cocaine during adolescence, compared with youth with later initiation of stimulant medication (≥10 years old) and shorter duration of prescription stimulant therapy (<1 year).

The investigators conducted a retrospective, multicohort survey study using data from the Monitoring the Future (MTF) cross-sectional nationally representative 10th grade (modal response rate, 88%) and 12th grade (modal response rate, 82%) student sample (N=150,395; 51.0% girls; 55% White, 11.6% Black, 15.6% Hispanic). The MTF study recruited from 16 annual surveys (conducted between 2005 and 2020, using self-reported paper questionnaires) from approximately 127 public and private US high schools.

Respondents were asked if they had ever taken a prescription stimulant for ADHD and given examples of some drug names. They were asked their age when they started using one of these prescription stimulants for ADHD (≤9 years of age, 10-14 years of age, or ≥15 years of age). They were asked how many years the stimulants were prescribed and if they had ever taken a nonstimulant prescription (with examples given of some drug names). They were also asked how many times (if any) during the past year they had used methamphetamine or cocaine.

The investigators found stimulant therapy for ADHD was used by an estimated 8.2% (n=10,937) of high school respondents during their lifetime. An estimated 36.7% of these students started using stimulant therapy at 9 years of age and younger. Use of nonstimulant therapy was reported by 3.3%. Overall, past-year prescription stimulant misuse was self-reported by 10.4% of students, past-year methamphetamine use was reported by 2.0%, and past-year cocaine use was reported by 4.4%.

There were significantly higher odds of past-year misuse of prescription stimulant, methamphetamine, and cocaine among adolescents who initiated late stimulant therapy for ADHD for a short duration vs non-ADHD and unmedicated ADHD students (controls). The investigators noted significantly higher odds of past-year misuse of prescription stimulant or cocaine among adolescents who initiated late stimulant therapy for ADHD for a short duration vs adolescents initiating early stimulant therapy for ADHD for a long duration.

No significant increase was reported in adjusted odds of past-year misuse of methamphetamine or cocaine among adolescents who initiated early stimulant therapy for ADHD for long duration vs controls. There were no differences in past-year misuse of prescription stimulant, methamphetamine, and cocaine among adolescents who initiated early stimulant therapy for ADHD for long duration vs adolescents who used nonstimulant therapy for ADHD.

Early stimulant therapy with long duration past-year cocaine use (adjusted odds ratio [aOR], 1.33; 95% CI, 0.93-1.93) was similar to past-year methamphetamine use (aOR, 1.71; 95% CI, 0.98-2.99) vs controls. The investigators noted higher odds for late stimulant therapy (beginning at age 15 years and older) with short duration past-year cocaine use (aOR, 2.34; 95% CI, 1.66-3.29) and past-year methamphetamine use (aOR, 1.99; 95% CI, 1.14-3.47) vs controls. Additionally, late stimulant therapy with short duration vs early stimulant therapy with long duration had higher odds of indicating past-year cocaine use (aOR, 1.74; 95% CI, 1.09-2.77). Past-year methamphetamine use odds were similar across both of the stimulant therapy groups.

Significant study limitations include the retrospective design, response bias — especially the self-reporting of illicit behavior by teenagers, missing data from segments of the youth population, and no assessment for ADHD severity or adverse childhood experiences associated with stimulant misuse. Additionally, given the cross-sectional study design, the investigators were not able to establish a causal link between medication therapy and substance use.

“An inverse relationship was found between years of stimulant therapy and illicit and prescription stimulant misuse,” the researchers reported. “The results suggest that early onset and longer duration of stimulant therapy for ADHD are associated with less cocaine or prescription stimulant misuse in late adolescence relative to later onset and shorter duration of stimulant therapy for ADHD,” they wrote. In conclusion, they stressed the need for monitoring for prescription stimulant, methamphetamine, and cocaine misuse among adolescents with later initiation and/or shorter duration of stimulant treatment for ADHD.

Disclosure: One of the study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.