by Dr. Mercola 
A study showed that neuroleptic drugs may cause problems far more serious than the ones they are meant to solve. The research showed that both an older neuroleptic (Haldol, also known as haloperidol) and a newer atypical neuroleptic (Zyprexa, also known as olanzapine) caused significant shrinkage in the higher level parts of the brains in monkeys.
Three groups of macaque monkeys were exposed to oral haloperidol, olanzapine or a placebo for a period ranging from 17 to 27 months. There was an 8 to 11 percent reduction in mean brain weight and left cerebrum weight and volume in both of the drug-treated groups.
According to Mind Freedom:
“The differences were observed across all major brain regions (frontal, parietal, temporal, occipital, and cerebellum), but was increased in the frontal and parietal regions in both gray and white matter.”