Researchers have now found that taking high doses of medications for ADHD (Attention-Deficit/Hyperactivity Disorder), particularly stimulants like amphetamines is linked to more than five times the risk of developing psychosis or mania.

ADHD is a neurodevelopmental disorder that affects the ability to maintain focus, remain still, and regulate impulses. The symptoms of ADHD often disrupt daily activities, academic performance, and social interactions. The condition typically gets diagnosed in children, but since there is no prevention or cure, it can continue into adulthood, manifesting differently as individuals age. The treatment involves a combination of therapy, parental training in behavioral management, and the use of stimulant and non-stimulant medications.

The use of stimulants for ADHD treatment has surged in the past decade, particularly during the COVID-19 pandemic. Earlier studies have established a connection between amphetamine use and an increased risk of psychosis. In the latest study, researchers explored how different dosage levels affect this risk.

The individuals involved in the study were patients hospitalized at Mass General Brigham's mental health facility, McLean Hospital, for incident psychosis or mania between 2005 and 2019. All patients were between the ages 16 and 35, the typical age of onset for psychosis and mania. Among these cases, there were 1,374 cases of first-episode psychosis.

Based on the health data, the researchers performed a comparative analysis of stimulant use over the past month while accounting for other factors such as substance use. This approach helped them isolate the effects of stimulants on the patients' conditions.

The findings published in the American Journal of Psychiatry suggest that individuals on prescription amphetamines in the past month were more likely to experience new-onset psychosis or mania compared to those who had not used them. The highest risk was in individuals taking 30 mg or more of dextroamphetamine, which is equivalent to 40 mg of Adderall.

While the risk of psychosis in participants exposed to any prescription amphetamine was found to be 63%, high-dose amphetamine use was linked to 81% risk. This means that among those taking amphetamine, 81% of cases of psychosis or mania could have been avoided if not taking a high dose.

"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. This is a rare but serious side effect that should be monitored by both patients and their doctors whenever these medications are prescribed," said lead study author Dr. Lauren Moran in a news release.

The study does not prove that stimulants directly cause psychosis, but the researchers suggest that there might be a biological link between the two. It is possibly because stimulants like amphetamines increase dopamine levels in the brain, and these changes in dopamine are similar to what happens in psychosis.

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