Discussion: Repeated, excessive intake of sugar created a state in which an opioid antagonist caused behavioral and neurochemical signs of opioid withdrawal. The indices of anxiety and DA/ACh imbalance were qualitatively similar to withdrawal from morphine or nicotine, suggesting that the rats had become sugar-dependent.
Colantuoni, C., Rada, P., McCarthy, J., Patten, C., Avena, N. M., Chadeayne, A. and Hoebel, B. G. (2002), Evidence That Intermittent, Excessive Sugar Intake Causes Endogenous Opioid Dependence. Obesity Research, 10: 478–488. doi:10.1038/oby.2002.66