High Doses of ADHD Meds Could Trigger Psychosis

Prescriptions for amphetamine stimulants to treat ADHD have increased significantly in recent years, particularly during the pandemic.

Unfortunately, high doses of stimulants like Adderall can increase the risk of psychosis or mania by more than fivefold, a new study finds.

Patients had a nearly 63% increased risk of psychosis or mania if they took any prescription amphetamine within the past month, researchers reported Sept. 12 in the American Journal of Psychiatry.

Those on heavy doses of amphetamines were at even greater peril of a psychotic episode, with an 81% increased risk, results show.

The highest risk occurred in patients taking 30 milligrams or more of dextroamphetamine, which corresponds to 40 milligrams of Adderall, the study says.

“Stimulant medications don’t have an upper dose limit on their labels, and our results show that it is clear that dose is a factor in psychosis risk and should be a chief consideration when prescribing stimulants,” said lead investigator Dr. Lauren Moran, a pharmacoepidemiology researcher at McLean Hospital in Belmont, Mass.

“This is a rare but serious side effect that should be monitored by both patients and their doctors whenever these medications are prescribed,” Moran added.

Moran said she pursued this study based on her experiences as an inpatient psychiatrist.

She and her Mclean colleagues would regularly see patients experiencing their first episode of psychosis. Medical records would reveal the patients had been prescribed high doses of stimulants by their doctors.

For the study, researchers analyzed data on nearly 1,400 patients admitted to Mass General Brigham Hospital between 2005 and 2019 who were in the throes of their first episode of psychosis or mania.

They compared those patients against more than 2,700 people hospitalized for other psychiatric conditions like depression or anxiety.

They found that people taking amphetamines had a higher risk of psychosis and mania, and that the risk was greatest with heavy doses.

This link could be explained by the fact that amphetamines prompt the release of dopamine, a brain hormone also implicated in psychosis, researchers said.

People taking amphetamines for ADHD shouldn’t be alarmed, Moran said, but they might want to talk with their doctor about the dosage they’ve been prescribed.

There also are alternative drugs to treat ADHD that don’t increase mental health risk.

For example, this study found no increased risk of psychosis or mania in prescriptions for methylphenidate (Ritalin), Moran noted.

“There’s limited evidence that prescription amphetamines are more effective in high doses,” Moran said in a Mass General Brigham news release. “Physicians should consider other medications our study found to be less risky, especially if a patient is at high risk for psychosis or mania.”

More information

The U.S. Centers for Disease Control and Prevention has more on treatment options for ADHD.

SOURCE: Mass General Brigham, news release, Sept. 12, 2024