Recent research highlights a concerning link between high doses of prescription amphetamines and an increased risk of psychosis or mania among teenagers and young adults. The study, published in the American Journal of Psychiatry on September 12, reveals that individuals taking 30 mg or more of dextroamphetamine—equivalent to 40 mg of Adderall—are over five times more likely to experience these severe mental health conditions.
Dr. Lauren Moran, the study’s lead author and a pharmacoepidemiology researcher at McLean Hospital, underscores the critical need to consider dosage when prescribing stimulant medications. “Our findings clearly show that the dose of amphetamines is a significant factor in psychosis risk,” Moran said. “This is a rare but serious side effect that should be monitored closely by both patients and healthcare providers.”
The analysis utilized electronic health records from Mass General Brigham, covering patient encounters from 2005 to 2019. Researchers focused on individuals aged 16 to 35, the typical age range for the onset of psychosis. The study involved 1,374 patients who experienced a first episode of psychosis or mania and 2,748 control patients with other psychiatric conditions. Results indicated that those using prescription amphetamines had more than double the odds of developing these severe mental health issues, with the risk amplifying over 13 times at the highest doses.
Interestingly, the study found no significant association between the use of methylphenidate and an increased risk of psychosis or mania, suggesting that the risk may be specific to certain stimulant medications and dosages.
Current ADHD treatment guidelines do not specify maximum dose limits, leading to variability in prescribing practices. The study advocates for a cautious approach, recommending that doses above 30 mg of dextroamphetamine equivalents be avoided to reduce the risk of psychosis.
Experts weigh in on the findings. Dr. Stephen Faraone from SUNY Upstate Medical University highlights that while the study provides valuable dose-related guidance, its observational nature means some factors, such as severity of prior psychiatric conditions, could not be controlled. Dr. Nina Kraguljac from Ohio State University emphasizes the need for careful consideration when prescribing high doses of amphetamines, particularly for individuals with a family history of psychosis.
Funded by the National Institute of Mental Health, this study adds to the growing body of evidence on the potential risks associated with stimulant medications, underscoring the importance of thoughtful dosing to safeguard mental health in younger populations.