A study of mice has identified a biological mechanism by which certain psychiatric medications cause people to gain weight.
Researchers linked the appetite-increasing effects of three such drugs—the so-called atypical antipsychotics clozapine (Clozaril), olanzapine (Zyprexa), and risperidone (Risperdal)—to their capacity to neutralize the protein histamine, just as the antihistamine drugs that are used to treat allergies do.
"Histamine also has a long history as a suspect in weight control," says neuroscientist Solomon Snyder of the Johns Hopkins School of Medicine in Baltimore. "The connection we've made ... opens new avenues for research on weight control, possibly including drugs that suppress appetite safely."
The new finding might also lead to safer treatments for schizophrenia and other manifestations of psychosis, Snyder and his colleagues say.