How antipsychotics cause side effects such as obesity and diabetes
Originally published January 31, 2012
In 2008, roughly 14.3 million Americans were taking antipsychotics—typically prescribed for bipolar disorder, schizophrenia, or a number of other behavioral disorders—making them among the most prescribed drugs in the U.S. Almost all of these medications are known to cause metabolic side effects such as obesity and diabetes, leaving patients with a difficult choice between improving their mental health and damaging their physical health. In a paper published January 31 in the journal Molecular Psychiatry, researchers reveal how antipsychotic drugs interfere with normal metabolism by activating a protein called SMAD3, an important part of the transforming growth factor beta (TGFβ) pathway.
The TGFβ pathway is a cellular mechanism that regulates many biological processes, including cell growth, inflammation, and insulin signaling. In this study, all antipsychotics that cause metabolic side effects activated SMAD3, while antipsychotics free from these side effects did not. What’s more, SMAD3 activation by antipsychotics was completely independent from their neurological effects, raising the possibility that antipsychotics could be designed that retain beneficial therapeutic effects in the brain, but lack the negative metabolic side effects.