(dailyRx News) Antipsychotic drugs are among the most prescribed drugs in the U.S. Almost all of these drugs are known to possibly cause obesity and diabetes, and, until recently, nobody knew why.
There were approximately 14.3 million Americans taking antipsychotics in 2008 for bipolar disorder, schizophrenia, and other behavioral disorders.
These people all face a difficult choice between mental health and physical health. A recent discovery may lead to new medication without these serious side effects.
Fred Levine, M.D., Ph.D., director of the Sanford Children's Health Research Center at Sanford-Burnham, says that “we now believe that many antipsychotics cause obesity and diabetes because they trigger the TGFbeta pathway.
Of all the drugs we tested, the only two that didn't activate the pathway were the ones that are known not to cause metabolic side effects."
The Transforming Growth Factor beta pathway (TGFbeta) is a cellular signal pathway that regulates biological processes such as cell growth and insulin signaling. Irregular insulin levels are related to metabolic diseases like diabetes.
The research team noticed that many antipsychotics change the activity of the insulin gene while doing research on diabetes. Lab experiments showed that these antipsychotics also activated the TGFbeta pathway.
Analysis of observations from schizophrenic patients confirmed the lab experiments. TGFbeta signaling was only activated in patients who were receiving antipsychotic medication.
The research team is hopeful that this discovery will lead to new medications that do not have the possibility of negative metabolic side effects.
"Having a dysregulated TGFbeta pathway—whether caused by antipsychotics or through some other mechanism—is clearly a very bad thing," says Dr. Levine.
"The fact that antipsychotics activate this pathway should be a big concern to pharmaceutical companies. We hope this new information will lead to the development of improved drugs."
The study was published in the journal Molecular Psychiatry on Jan. 31, 2011, and funded by a gift from Mr. T. Denny Sanford to the Sanford Children's Health Research Center at Sanford-Burnham.