No Evidence of Substance Abuse in Patients Taking Stimulant Medication for ADHD

Data from a new cohort study suggested stimulant treatment for attention deficit/hyperactivity disorder (ADHD), which is predominantly prescribed during childhood and adolescence, does not appear to increase or decrease the risk of later substance use among individuals with ADHD.¹

ADHD affects a significant number of children worldwide. Stimulant medications are commonly prescribed as a treatment for ADHD, but concerns have been raised about their potential association with substance use later in life.²

To address these concerns, Brooke S. G. Molina, PhD, Departments of Psychiatry, Psychology, & Pediatrics, University of Pittsburgh, and investigators conducted a recent cohort study, known as the Multimodal Treatment Study of ADHD (MTA) which examined the long-term effects of stimulant treatment on substance use among individuals with ADHD.¹

The study was initially a 14-month randomized clinical trial conducted at 6 sites in the United States and 1 in Canada, focusing on medication and behavior therapy for ADHD. The trial transitioned into a longitudinal observational study, recruiting participants between 1994 - 1996. A total of 579 children, with a mean age of 8.5 years (SD, 0.8), were included in the analysis and 80% were male.

Multi-informant assessments were utilized to collect comprehensive data on demographic, clinical, and treatment variables, including substance use and stimulant treatment. Treatment was measured prospectively from baseline for 16 years, using parent reports initially, followed by young adult self-reports.

The main outcomes measured included the frequency of heavy drinking, marijuana use, daily cigarette smoking, and other substance use, which were self-reported confidentially using a standardized substance use questionnaire.

Investigators followed participants up to a mean age of 25 years. Generalized multilevel linear models and marginal structural models were used to examine the association between stimulant treatment and substance use.

After adjusting for developmental trends in substance use and age, the analyses revealed no evidence to support an association between current or prior stimulant treatment and substance use. The estimated regression coefficients (B) and standard errors (SE) for the association between stimulant treatment and substance use were not statistically significant.

According to the findings, no evidence of an association was found between current or prior stimulant treatment and substance use. For current stimulant treatment, the regression coefficients (B) ranged from -0.62 to 0.34, with corresponding standard errors (SE) ranging from 0.55 to 0.47.

Similarly, for prior stimulant treatment, the regression coefficients (B) ranged from -0.06 to 0.70, with corresponding standard errors (SE) ranging from 0.26 to 0.37. The interaction between stimulant treatment and substance use also showed no significant association, with regression coefficients (B) ranging from -0.49 to 0.86 and standard errors (SE) ranging from 0.70 to 0.68.

The findings remained consistent when assessing substance use disorder as an outcome.

The team emphasized that results consistently showed no statistically significant associations between stimulant treatment and substance use or substance use disorder. These data provide valuable evidence to inform clinical decision-making regarding the long-term effects of stimulant medication and suggest that concerns about stimulant treatment potentially leading to substance abuse should be reevaluated, as they do not seem to be supported by the available data, they wrote.

References:

1. Molina BSG, Kennedy TM, Howard AL, et al. Association Between Stimulant Treatment and Substance Use Through Adolescence Into Early Adulthood. JAMA Psychiatry. Published online July 05, 2023. doi:10.1001/jamapsychiatry.2023.2157
2. Kunzmann K. Study: Half of US Adults Report Prescription Drug Misuse. HCPLive. January 5, 2022. https://www.hcplive.com/view/study-half-us-adults-report-prescription-drug-misuse