Researchers at University of Rochester Medical Centre say that the antipsychotic drug, clozapine has some very concerning side effects. Clopazine is the most effective anti-psychotic drug available.

"Clozapine is the last hope for many people. But there are long-term health implications. This study suggests that patients who need the most effective medication are between a rock and a hard place," said J. Steven Lamberti, the lead author of the study.

The study found that clozapine increased the risk of metabolic syndrome, a group of conditions that increase the risk for heart disease, stroke and diabetes.