The volume of certain brain areas is temporarily reduced within hours of antipsychotic drug treatment reports a study published online in Nature Neuroscience. The work finds that this rapid reduction correlated with the degree of movement disorders, a common side-effect of some antipsychotic drugs.
Many antipsychotic drugs used to treat schizophrenia block the receptor for the neurotransmitter dopamine. These drugs, however, cause undesired movement disorders called extrapyramidal symptoms (EPS) which includes slowing of movements. Because EPS can occur within minutes of antipsychotic treatments, Heike Tost and colleagues examined whether there are corresponding structural changes in the brain. Within hours after a single drug treatment in healthy young men, the scientists found that the antipsychotic drug haloperidol caused a temporary grey matter volume reduction in the ventral putamen ― a brain region important for movement. Brain volumes returned to normal levels within 24 hours.
The team found that the severity of EPS in healthy subjects was positively correlated with the degree of brain volume reduction. The time course of motor impairment closely resembled the rapid changes in brain structure and connectivity. This study suggests that short-term structural changes in the brain may be responsible for some side-effects of antipsychotic medication in humans.