Table 2. Action of typical and atypical antipsychotics on DNA demethylation. a mg/kg: drugs were given s.c. twice a day for 3 days. b DNA demethylation refers to reelin and GAD67 promoter demethylation. Under basal conditions, 10% of methionine-induced hypermethylated reelin or GAD67 promoters is demethylated in 3 days after methionine withdrawal. (+) = 30-35% increase DNA demethylation over basal activity.(+++) = 75-90% increase DNA demethylation over basal activity. Data from ref 79.
| Drug | mg/kga | DNA demethylationb |
| Clozapine | 1.25 | +++ |
| Olanzapine | 10 | + |
| Quetiapine | 10 | + |
| Haloperidol | 1.5 | - |
| Risperidone | 10 | - |
| Sulpiride | 20 | ++ |