Endogenous codeine and morphine in anorexia and bulimia nervosa.

The endogenous plasma alkaloids codeine and morphine were shown to be elevated in patients with anorexia nervosa and bulimia nervosa compared to control subjects. The role of these opioids in the pathophysiology of these eating disorders is discussed in relation to an auto-addiction opioid model. This model proposes that endogenous opioids are released during an initial period of dieting and reinforce a state of starvation dependence [1,2].