The first non-dopamine schizophrenia drug in 70 years

Nearly every antipsychotic since the 1950s has blocked dopamine. A muscarinic drug works a completely different way.

For over 70 years, almost every antipsychotic has worked the same fundamental way, by blocking the brain’s dopamine D2 receptors. That approach helps many people, but it often does little for the “negative” symptoms (like flattened emotion and social withdrawal) and cognitive problems that most shape day-to-day life, and it can bring heavy side effects. This review charts a genuine turning point. In 2024, the FDA approved KarXT, a first-in-class drug that skips dopamine entirely and instead activates muscarinic acetylcholine receptors (specifically the M1 and M4 subtypes), the first non-D2 antipsychotic mechanism in more than seven decades. Late-stage (Phase III) trials show it improves both positive and negative symptom domains, with a favorable metabolic profile: no clinically meaningful weight gain or blood-sugar disruption, unlike many older drugs. Early hints suggest possible cognitive benefits for those who start with impairment, though that needs confirmation, and long-term safety data are still limited. The review also covers a second experimental route, glutamate-targeting drugs like GlyT1 inhibitors, but there the trial results have been inconsistent, leaving that path uncertain. The big picture: muscarinic drugs are the first proven alternative to the dopamine playbook, opening a real new direction for a disorder where progress has been painfully slow.