- Evidence of neurochemical similarities between substance addiction and obesity comes from studies showing that similar to individuals with drug addiction, obese individuals have decreased striatal D2 receptor availability and demonstrate elevated levels of DA metabolism.
- Such findings suggest dysfunction within the brain reward mechanisms of individuals with obesity.
- Partial blockage of these same pathways by antipsychotics has been associated with overeating and increased risk for obesity.
- Animal models have further supported this finding.
- Bingeing on both high sucrose and high fat foods has been shown to elicit DA release in the nucleus accumbens in animals.
- Animal models have also shown that bingeing is associated with down-regulation of D2-receptor mRNA and an increase in D3-receptor mRNA in the nucleus accumbens.
- Interestingly, these dopaminergic changes seen in response to bingeing are the same as those observed in obesity and drug dependency.
References
- Johnson PM, Kenny PJ. Dopamine D2 receptors in addiction-like reward dysfunction and compulsive eating in obese rats. Nature neuroscience. 2010; 13(5), 635-641.
- Koob GF, Volkow ND. Neurocircuitry of addiction. Neuropsychopharmacology. 2010; 35(1), 217-238.
- Avena NM, Bocarsly ME, Hoebel BG. Animal models of sugar and fat bingeing: relationship to food addiction and increased body weight. Methods in molecular biology. 2012; 829, 351-365.
- Avena NM, Bocarsly ME, Hoebel BG, Gold MS. Overlaps in the nosology of substance abuse and overeating: the translational implications of “food addiction”. Current drug abuse reviews. 2011; 4(3), 133-139.
