NIH symposium series: ingestive mechanisms in obesity, substance abuse and mental disorders.

This report summarizes the background and specific objectives for a symposium on the neurobiology of nonhomeostatic eating and drug abuse that was held at the 2004 Annual Meeting of the Society for the Study of Ingestive Behavior (SSIB). The symposium was the first of a series funded by a conference grant from four institutes of the National Institutes of Health. The encompassing goal of the series is to analyze the roles for the biological mechanisms of ingestion in obesity, eating disorders and other theoretically related areas including addiction, depression and schizophrenia. The symptoms and treatments of these diverse pathologies routinely involve aberrations in the mechanisms regulating eating and body weight. The presentations and discussion from this symposium (1) identified changes in neurotransmitter dynamics and gene expression in brain "reward circuits" accompanying learning of behaviors to obtain palatable foods or drugs of abuse; (2) analyzed behavioral findings in animals and humans, and neuroimaging data in humans, supporting treatment with GABA(B) agonists to reduce craving for drugs of abuse and possibly for highly rewarding foods; and (3) used neuroimaging data in humans to establish novel serotonergic targets for normalizing reward processes and impulse control in anorexia nervosa and bulimia. Overall, the symposium clearly revealed our rapidly broadening understanding of the alterations in the brain at the molecular, cellular and systems levels that are associated with craving and nonhomeostatic consumption of food and drugs of abuse. This knowledge gained largely in animal models translates to novel and better strategies for treating human patients.