Figure 3.

Proposed model of hedonic/reward response to ghrelin after chronic stress in relation with anxio-depressive symptoms. During chronic stress, increased ghrelin secretion has been shown to induce emotional eating by acting at the level of the hedonic/reward system. As ghrelin has been shown to have anxiolytic actions in response to stress, this adaptative response may contribute to control excessive anxiety and prevent depression. In obesity, lower ability to mobilize ghrelin in response to stress or central ghrelin resistance at the level of the hedonic/reward system may explain the inability to cope with anxiety and increased susceptibility to depression. Reciprocally, depressed subjects have increased susceptibility to obesity or eating disorders (due to altered hedonic/reward response). Elevated ghrelin may also contribute to alcohol/drug craving: higher ghrelin levels correlate with higher measurements of alcohol craving.