The endogenous plasma alkaloids codeine and morphine were shown to be
elevated in patients with anorexia nervosa and bulimia nervosa compare
d to control subjects. The role of these opioids in the pathophysiolog
y of these eating disorders is discussed in relation to an auto-addict
ion opioid model. This model proposes that endogenous opioids are rele
ased during an initial period of dieting and reinforce a state of star
vation dependence [1,2].