A highly popular study in 2024 American Journal of Psychiatry (Moran et al. 2024) showed that people like drugs Adderall for attention– attention deficit/hyperactivity disorder (ADHD) is five times more common psychosis.
At higher clinical doses (about 30 mg of dextroamphetamine or 40 mg of Adderall), amphetamine-based drugs have been associated with hallucinations and persecutory delusions. The study found that 81 percent of these cases could have been prevented with lower doses.
The study found that it wasn’t just the very high doses that were dangerous. Even those who take moderate doses are more likely to develop psychosis than people who don’t take them.
The media saw the research as a surprising, even scandalous, discovery. Psychiatrists have been quick to reassure the public that such side effects are rare. But the connection between amphetamines and psychosis is not new. This is one of the oldest findings of modern psychiatry.
In 1967, a doctor used amphetamines to deliberately induce psychosis in normal volunteers.
So how can we forget this lesson? And how does knowing its history help shape the future?
Discovering Amphetamine Psychosis
Amphetamine psychosis was first named in 1953 by the British physician PH Connell. The patient came to London’s Maudsley Hospital experiencing hallucinations, delusions and hallucinations. paranoia. He heard voices and became convinced that his master was trying to kill him over a patent dispute.
Connell hospitalized him with a diagnosis of schizophrenia. After a few days, the symptoms disappeared. Careful observation revealed that his psychosis was caused by large amounts of amphetamines. (At the time, amphetamines were available over the counter as decongestants.)
Connell wondered if other doctors had reported such strange side effects of amphetamines. He asked his colleagues and started going through the case files. He thought he could find three or four cases in the medical literature.
He found 42.
He was surprised that the link between amphetamines and psychosis was not better known. wrote a book called Amphetamine psychosis to document their findings. He argued British Medical Journal for stricter restrictions on their sale.
But Connell’s demands were largely ignored. The problem is that amphetamines were considered the wonder drug on par with penicillin. By the 1940s, amphetamines were prescribed for fatigue, narcolepsy, ADHD, weight loss, and more. depression. Doctors say that amphetamines can even restore a certain “taste” of life bored housewives and tired entrepreneurs.
No one wanted to think they were a pill that would make you crazy.
A quest to create madness
Amphetamine psychosis was rediscovered in the United States in the late 1960s due to the epidemic of injection amphetamine use.
In the early 1960s, doctors in Southern California wanted to help heroin users get clean by prescribing vials of methamphetamine. They thought that injecting amphetamine was safer and less addictive.
This bad decision created a large subculture of intravenous amphetamine users – “Speed Freaks”. They often develop hallucinations and paranoid delusions. Speed users regularly show up in mental hospitals and are often misdiagnosed with paranoid schizophrenia.
One doctor was so impressed by the connection between amphetamines and psychosis that he tried to do just that induces psychosis in normal volunteers. He believed that a pill that could reliably create a schizophrenia-like state would benefit mental health research.
He gathered four groups of volunteers – recreational speed users – and gave them amphetamine pills until they became psychotic. This experiment showed that amphetamines can induce psychosis in people with no history of mental illness. His experience was also the basis the dopamine hypothesis of schizophreniait changed psychiatry in the 1970s.
The link between amphetamine use and psychosis was briefly rediscovered in the late 1980s thanks to an article published in the late 1980s. Journal of Emergency Medicine documented 127 cases (Derlet et al. 1989). The authors noted that such patients were often misdiagnosed because doctors did not understand that psychosis was related to amphetamine use.
Basic readings of psychosis
A forgotten lesson
So why do we forget this lesson? Why was it such a surprise when a 2024 paper found a link between amphetamine-based drugs like Adderall and psychosis?
One reason for this is that although doctors knew that amphetamines could cause psychosis, they believed that amphetamines were mostly abused in large doses—well above those prescribed for conditions such as ADHD.
As long as people took clinically proven doses, they were not expected to experience psychosis as judged by a doctor.
Another reason, I think, is precisely the one faced by PH Connell: no one wants to think that we are collectively putting young people at risk of psychosis. In 2022, nearly 7 million American children will be diagnosed with ADHD; that’s about one in 10 children. About half of them enabled drug.
So what does that mean? Does this mean that no one uses drugs like Adderall? No, not at all. Adderall can certainly be helpful for some people at certain stages of their lives.
But it does mean we need to stop treating amphetamine-induced psychosis as a surprising anomaly and start recognizing it as a well-documented risk—one that psychiatry has discovered, forgotten, and rediscovered for 70 years.
This post is adapted from my book, The Madness Pill: One Doctor’s Quest to Understand Schizophrenia (St. Martin’s Press, 2026).
