Indeed, studies have shown that prolactin-elevating antipsychotics, such as risperidone, penetrate the blood-brain barrier poorly, therefore occupying the D2 receptors much longer in the pituitary (peripheral) than the striatum (central) and leading to a prolonged hyperprolactinemia, which is closely correlated with BMD loss. The gene discussed is PRL; the disease is hyperprolactinemia.