Do Orexins contribute to impulsivity-driven binge consumption of rewarding stimulus and transition to drug/food dependence?

Orexins (OX) are neuropeptides synthesized in the lateral hypothalamic region which play a fundamental role in a wide range of physiological and psychological functions including arousal, stress, motivation or eating behaviors. This paper reviews under the addiction cycle framework (Koob, 2010), the role of the OX system as a key modulator in compulsivity-driven consumption of rewarding stimulus including ethanol, palatable food and drugs and their role in impulsivity and binge-like consumption in non dependent organisms as well. We propose here that drug/food binge-like consumption in vulnerable organisms increases OX activity which, in turn, elicits enhanced impulsivity and further impulsivity-driven binge consumption in a positive loop that would promote compulsive-driven binge-consumption and the transition to drug/food disorders over time.