Can stimulants for ADHD cause Psychosis?
A recent study from USA looked at health care insurance claims in people started on a stimulant medication (methylphenidate or amphetamine) for ADHD. The people included in the study were aged between 13 and 25. The study found that out of the 221,846 people included, 343 (0.1%) experienced psychosis which required medical treatment. Psychosis is an experience where the boundaries of realty become blurred, and impact functioning, such as disordered thinking, delusions and hallucinations.
Of the 343 people who developed psychosis, 237 were prescribe amphetamine, and 106 prescribed methylphenidate. This suggests methylphenidate is less likely to cause psychosis. The researchers calculated that a person was 65% more likely to develop psychosis from amphetamine prescription. However, the overall risk of developing psychosis with either medication is very small, and it is not clear how many of the 343 people would have developed psychosis despite their prescribed stimulant. However, for people who might be vulnerable to psychosis, methylphenidate is likely a preferred choice for them.
Source: Moran et al. Risk of psychosis with amphetamine versus methylphenidate in attention deficit hyperactivity disorder. Pharmacoepidemiology and Drug Safety. 2019;28:41