Antipsychotics make you dumb and shrink your brain.

A leading antipsychotic drug temporarily reduces the size of a brain region that controls movement and coordination, causing distressing side effects such as shaking, drooling and restless leg syndrome.
Just two hours after injection with haloperidol, an antipsychotic commonly prescribed to treat schizophrenia, healthy volunteers experienced impaired motor abilities that coincided with diminished grey-matter volume in the striatum1 — a brain region that mediates movement.
"We've seen changes in the brain before, but to see significant remodelling of the striatum within a couple of hours is staggering," says Clare Parish at the Howard Florey Institute for brain research in Melbourne, Australia, who was not involved in the study. "Our viewpoint was that only chemical changes would happen in such a short time."
In functional magnetic resonance imaging (fMRI) scans the authors observed the participants' striatal volume diminishing and changes to the structure of the motor circuitry in their brains. Further, their reaction times slowed in a computer test taken after the treatment, indicating the onset of lapses in motor control that affect many patients on antipsychotics.
Dopamine downsizing

Haloperidol has a number of side effects, although many of these are minor and recede within weeks of starting treatment. With few better alternatives, psychiatrists have prescribed the drug for more than 40 years to treat people suffering from hallucinations, delirium, delusions and hyperactivity.
Like most antipsychotics, haloperidol blocks the D2 receptor, which is sensitive to dopamine. The drug stifles the elevated dopamine activity that is thought to underlie psychosis. D2 receptors are abundant in the striatum, where their activity regulates gene expression. But, until now, no one knew that blocking the receptors would rapidly alter the brain's physical structure.