A recent study published in the New England Journal of Medicine assessed the risk of new-onset psychosis among adolescents and young adults with attention deficit hyperactivity disorder (ADHD) initiated on various stimulant medications.
Using data from 2 insurance claims databases, the researchers identified patients 13–25 years old with an ADHD diagnosis who received treatment with either methylphenidate or amphetamine and were newly diagnosed with psychosis (ICD-9 or ICD-10 code for psychosis and a prescription claim for antipsychotic medication). “To estimate hazard ratios for psychosis, we used propensity scores to match patients who received methylphenidate with patients who received amphetamine in each database, compared the incidence of psychosis between the 2 stimulant groups, and then pooled the results across the 2 databases,” the authors explained.
Results showed that among patients treated with methylphenidate (N=110,923), there were 106 episodes of psychosis (incidence of psychotic episode: 1.78 per 1000 person-years), while among those treated with amphetamine (N=110,923), there were 237 episodes (incidence of psychotic episode: 2.83 per 1000 person-years). In the propensity-score matched population, amphetamine use was associated with an increased risk of psychosis compared with methylphenidate use (pooled hazard ratio 1.65; 95% CI, 1.31 to 2.09).
Based on their findings, the authors concluded that new-onset psychosis occurred in roughly 1 in 660 ADHD patients receiving prescription stimulants, however, this risk was found to be almost twice as high in amphetamine initiators vs methylphenidate users.
For more information visit nejm.org.