The idea behind this type of therapy is that one wants to alleviate the temptation of a particular stimulus that results in unwanted behaviour. The punishment involves either removing a positive reinforcer or presenting an aversive stimulus following the undesired behaviour. The most commonly used type of aversive stimulus is electric shock, although its use has declined in recent years. Certain types of drugs with aversive effects (e.g. nausea/vomiting) are also used (e.g. with alcohol). Positive reinforcement of behaviours that are incompatible with the undesired behaviour is being used more often today. Aversion therapy has been used in treatment of a variety of behaviours, including smoking, drinking, overeating, dependence on drugs, and gambling.