Prescription amphetamine use may induce psychosis, mania

Use of prescription amphetamines appears to increase the risk of incident psychosis or mania, according to a US study. 

This case-control study used electronic health records to compare the likelihood of incident psychosis or mania with past-month exposure to prescription amphetamines. 

Researchers included 1,374 patients aged 16–35 hospitalized for incident psychosis or mania between 2005 and 2019, as well as 2,748 control participants with an initial psychiatric hospitalization for other reasons, such as depression or anxiety. 

Amphetamine doses had been converted to dextroamphetamine equivalents and divided into terciles. In secondary analyses, the research team assessed the odds of psychosis and mania with the use of methylphenidate. 

Individuals with past-month prescription amphetamine use were more likely to develop psychosis or mania than those with no use (adjusted odds ratio [aOR], 2.68, 95 percent confidence interval [CI], 1.90–3.77), with higher amphetamine doses (>30 mg dextroamphetamine equivalents) correlating with a 5.28-fold increased likelihood of psychosis or mania. 

On the other hand, past-month use of methylphenidate showed no significant association with a higher likelihood of developing psychosis or mania relative to no use (aOR, 0.91, 95 percent CI, 0.54–1.55). 

“Although use of hospitalized control subjects excludes individuals with less severe disease, leading to selection bias, the study results suggest that caution should be exercised when prescribing high doses of amphetamines, with regular screening for symptoms of psychosis or mania,” the researchers said.