Safety of Stimulants Across Patient Populations: A Meta-Analysis.

IMPORTANCE

The use of stimulant medications has expanded substantially beyond the traditional treatment of attention-deficit/hyperactivity disorder (ADHD) to encompass a variety of other clinical conditions. Understanding the safety of these medications is important as their use increases across diverse patient populations.

OBJECTIVE

To assess the safety of stimulant medications as reported in randomized clinical trials (RCTs) investigating methylphenidate, lisdexamfetamine, and other amphetamines.

DATA SOURCES

A comprehensive literature search was conducted from July 1, 2024, through February 28, 2025, using CINAHL, Embase, PubMed or MEDLINE, ScienceDirect, and Web of Science for studies published since 2000. Keywords included safety, adverse event, side effect, amphetamine, dextroamphetamine, stimulant, lisdexamfetamine, and methylphenidate.

STUDY SELECTION

RCTs published between January 1, 2000, and December 13, 2024, were included. These trials investigated the safety of stimulants in various clinical conditions, including ADHD, depression, binge eating disorder, schizophrenia, Alzheimer disease, and stimulant use disorders as well as in healthy individuals. Trials not focused on safety or adverse events (AEs) of stimulants, nonoriginal research, nonhuman research, trials with concomitant prescriptions other than stimulants, and trials without a placebo group were excluded.

DATA EXTRACTION AND SYNTHESIS

Data extraction followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guideline. Independent reviewers extracted study data, and a random-effects model was used to pool results. Heterogeneity was assessed using the I2 statistic.

MAIN OUTCOMES AND MEASURES

The primary outcome was the risk ratio (RR) of developing any AE in participants taking stimulants vs placebo.

RESULTS

A total of 93 RCTs were included after exclusions. The methodological quality assessment of the included trials showed overall low or unclear risk of bias. Trials with a duration of up to 52 weeks showed that stimulant medications were associated with an increased risk of overall AEs compared with placebo (RR, 1.34; 90% CI, 1.27-1.41), with high heterogeneity (I2 = 67%). Statistical significance of this finding was maintained when subgroups (ie, methylphenidate, lisdexamfetamine, and other amphetamines) were separately analyzed.

CONCLUSIONS AND RELEVANCE

This meta-analysis found an increased risk of overall AEs associated with stimulants compared with placebo. Future research could provide more standardized and consistent assessments of this outcome and may improve understanding about misuse risk.