Antipsychotics and Weight Gain

The reason that antipsychotic medications cause weight gain is that there is increased activity of the enzyme AMP-kinase in the hypothalamus, the area of the brain that controls hunger. The increase in AMP-kinase levels occurs because antipsychotic medications interfere with the protein histamine. For some time it has been suspected that histamine plays a significant role in weight control, and these findings, from a study conducted in mice by scientists at Johns Hopkins University, confirm this. The researchers hope that these findings will contribute to the development of a new class of effective antipsychotics that do not cause weight gain.

(Source: Kim SF, Huang AS, Snowman AM, et al. Antipsychotic drug-induced weight gain mediated by histamine H1 receptor-linked activation of hypothalamic AMP-kinase. Proc Natl Acad Sci U S A. 2007;104:3456-3459.