aversion therapy is based on classical conditioning, relating to the idea that two stimuli will become associated if they occur repeatedly at the same time
aversion therapy uses counterconditioning to change the association of addictive behaviours with something pleasant to something unpleasant e.g., instead of being associated with pleasure, it becomes associated with the sickness of taking an emetic
other aversive stimuli include electric shocks e.g., received when gamblers use phrases relating to gambling or rapid smoking inducing sickness