Adults taking high doses of medication for ADHD are five times more likely to suffer from psychosis or manic episodes, according to a US study from McLean Hospital.
The study, published in the American Journal of Psychiatry, is based on data from patients hospitalized for psychosis or mania between 2005 and 2019. The patients, who were between 16 and 35 years old, had no previous history of these conditions. The researchers also used a control group of patients who had been hospitalized for other mental health conditions, such as anxiety or depression, but not psychosis or mania.
The patients were admitted through the emergency department of Mass General Brigham Hospital in Massachusetts.
The study found that people who had used amphetamine-based drugs in the past month were at a significantly higher risk of developing psychosis or mania compared to those who had not taken such drugs. The risk was over two times higher in these individuals. In total, the researchers found that 63% of all psychosis or mania cases among amphetamine users could have been avoided if the drug had not been taken.
Furthermore, they found that increased doses of amphetamine-based drugs were linked to a higher risk of psychosis or mania. Patients taking 30 milligrams or more were five times more likely to develop these conditions, according to the researchers.
Authors urge caution
The researchers estimated that up to 81% of psychosis or mania could have been avoided by reducing the dose of the drug.
However, the study found no increased risk of psychosis or mania in patients using methylphenidate-based drugs, such as Ritalin, compared to those not using such medications.
The researchers urge doctors to be more cautious when prescribing these drugs, especially to patients with risk factors for psychotic or manic episodes.
– 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 the study’s lead author Lauren Moran, who researches pharmacoepidemiology at McLean Hospital, in a press release.