Addiction A-Z

Aversion therapy

Aversion therapy is a behavioral treatment intervention based on the principles of classical conditioning and behavioral psychology.  It is sometimes referred to as conversion therapy or reparative therapy.

The goal of aversion therapy is to eliminate bad habits, self-destructive behaviors, or other undesirable behaviors (e.g. nail biting or alcohol abuse) by pairing the behavior with an unpleasant stimulus (e.g. medication-induced nausea or an electrical shock).  The assumption is that the problematic behavior is a learned behavior, and as such, can be “unlearned” or changed with proper “conditioning”.

Remember Pavlov and his salivating dogs?  The conditioning that occurs in aversion therapy very is similar in many ways to Pavlov’s famous experiment.  By ringing a bell just prior to feeding them, the dogs became conditioned to salivate at the sound of the bell.  This is because they learned to associate the sound with food (if you have pets you’ve likely observed something similar!).

Aversion therapy works along the same lines, except unlike the dogs associating the bell with something positive, aversion therapy works to create an association with something negative.  If Pavlov had used a device to emit a high frequency whistle (at a pitch that irritates dogs’ ears) every time they started to eat – instead of using a bell – they would have quickly learned to avoid eating the food to avoid the irritating sound.  The negative stimulus – the high-pitched whistle – would cause them to develop an aversion to eating the food.   (Fortunately for his dogs Pavlov wasn’t using this version of the conditioning experiment!)

Aversion therapy is designed to cause individuals to develop an intense dislike or feeling of disgust – an aversion – to the behavior itself as they come to associate it with the noxious stimulus.  The impact of the unpleasant stimulus must occur immediately or very soon after the behavior in order for the association to be made.  Perhaps you can recall something you ate that made you horribly sick to your stomach just a few minutes later.  Chances are you avoided that food for a very long time (or perhaps still do!) because you associate eating it with an adverse reaction – one you don’t want to experience again.  That’s essentially how aversion therapy works.

Individuals who habitually bite their fingernails will eventually stop the behavior if they experience a nasty taste (from a topical formula applied to the nails) every time they start to bite their nails.  Alcoholics who take disulfiram (the generic name for Antabuse) learn to avoid alcohol because they’ll quickly experience awful side effects if they have a drink.  These are both examples of aversion therapy.

In aversion therapy, the behavior doesn’t necessarily have to actually take place in order to use the therapy or apply the stimulus.  For example, with some types of problems the therapist may have therapy clients imagine themselves engaging in the unwanted behavior or look at an object or photograph that elicits an undesirable response (e.g. sexual arousal).  With each type of exposure (fantasy, object, or photograph) the unpleasant stimulus is introduced.  For example, if the goal is to curb homosexual desires and behavior, the therapist may instruct clients to view homosexual pornography or picture themselves being intimate with a same-sex partner while the therapist administers an electrical shock or other unpleasant stimulus.

This entire process is repeated over and over until the individual eventually stops associating pleasure with the unwanted behavior and associating it, instead, with the negative experience caused by the unpleasant stimulus.  Unfortunately, since aversion therapy isn’t always effective – especially when it’s used to treat something like homosexuality – this process can go on for a very long time.  This is one of the reasons it’s such a controversial form of therapy.  (The criticisms of aversion therapy are discussed below.)

Although aversion therapy can potentially be used to help eliminate almost any unwanted behavior, two of the most common applications of this treatment approach over the years are rehabilitation programs for sex offenders and drug and alcohol addiction treatment.

Types of Stimuli Used in Aversion Therapy

While different types of negative stimuli can be used in aversion therapy, there are three types that are used most frequently – electrical shocks, chemical stimuli, and olfactory or gustatory stimuli.

Electrical shock – This type of stimulus has been widely used to treat a variety of unwanted behaviors, inclinations, and conditions. The use of electrical shock is perhaps the most controversial form of aversion therapy. It involves administering an electrical shock via a device that is attached to some part of the body, such as the arm, leg, or genitals. The individual receives a shock every time he or she engages in the unwanted behavior.  Aversion therapy using electrical shocks has been used to treat addiction and other types of unwanted or unacceptable behavior.

This form of aversion therapy has been widely used to inhibit homosexual behaviors and desires and, by doing so, “cure” homosexuality.  An example of this application involves having individuals view homoerotic images and administering a shock every time they are sexually aroused by the images.

Advantages of using electrical stimuli include:

  • Fewer potential adverse or unexpected side effects
  • Therapist has complete control over the negative stimulus
  • Less expensive than other types
  • Ease of administration

Chemical stimuli – This type of stimulus consists of a substance or medication that has a disgusting taste or causes highly unpleasant side effects.  As mentioned above, disulfiram (Antabuse) is an example of a chemical stimulus used in aversion therapy for alcohol addiction.  Individuals who are taking disulfiram experience a variety of negative side effects if they consume alcohol.  The disulfiram disrupts the way alcohol is normally metabolized in the body, causing side effects to occur within 10 minutes after taking a drink.  Side effects can last for several hours and may include nausea, vomiting, heart palpitations, intense headache, flushing, shortness of breath, and dizziness.  Just knowing that they’ll have to endure such nasty side effects is enough to help some alcoholics resist temptation.

One of the main advantages of using chemical stimuli is that it can be quite effective for some individuals and types of behavior.  However, there are some potential disadvantages to this approach compared to other types that must be considered. They include:

  • Greater potential for unexpected or serious negative side effects (e.g. disulfiram can make some individuals very ill)
  • Less therapist control over administration of the stimulus
  • Chemical aversion therapy can be quite expensive, particularly when it requires medical supervision.  Some forms of chemical aversion therapy are done in a hospital or residential treatment setting (e.g. chemical aversion therapy with alcohol or drug addiction), adding further to the overall cost.

Olfactory or gustatory stimuliThe term olfactory pertains to the sense of smell, while the term gustatory pertains to the sense of taste.  Used far less frequently than other aversion therapy methods, the use of these stimuli involves exposure to an intensely foul odor or taste, such as ammonia (one of the most frequently used olfactory stimuli), each time the person engages in or imagines doing the unwanted behavior.

Olfactory aversion techniques have been used in the treatment of homosexuality as well as children and adolescents who were considered sexually deviant.  A bitter-tasting substance painted on the fingers of compulsive nail biters would be considered a type of gustatory stimuli.

Covert Sensitization

Covert sensitization, also known as verbal aversion therapy, is a specific type of aversion therapy that doesn’t involve the use of physical or “overt” stimuli – such as electrical shocks or nausea-inducing medications – to form an association between the undesirable behavior and an unpleasant effect or consequence.  Instead, it relies on the individual’s imagination to produce the unpleasant “covert” stimuli.

For example, an alcoholic using covert sensitization would vividly imagine a highly disturbing or unpleasant consequence of drinking, such as horrible nausea and vomiting (similar to that caused by Antabuse).   Someone who’s struggling with overeating (particularly if it involves a specific food like chocolate or ice cream) could vividly imagine the desired food covered in something repulsive, such as live maggots or cat urine.

The primary advantage of this form of aversion therapy is that no actual consequences or suffering (e.g. the pain or discomfort of an electrical shock or the negative side effects of a drug) are actually experienced – they’re only imagined.  By removing the actual consequences, the ethical issues – and potential physical (and psychological) risks – are also eliminated.  This is one of the reasons covert sensitization is considered a more acceptable and preferable form of aversion therapy by many.

Another advantage of covert sensitization is that the client is in complete control of whatever he or she imagines.  The therapist does assist the client to ensure that the image has sufficient details (to maximize its impact) and is suitable for the particular individual.

However, covert sensitization is not without disadvantages.  For example, if the imagined consequence isn’t intensely disturbing it won’t have enough of an impact to be effective.  Also, while other types of aversion therapy (that utilize overt stimuli) can be used with most individuals, covert sensitization typically works best with individuals whose motivation is high.

Uses of Aversion Therapy

Since aversion therapy is used to eliminate problematic behaviors and unwanted desires, its uses are more limited than talk therapy and many other types of psychotherapy.  Disorders, conditions, and problems for which aversion therapy is most frequently used include:

  • Drug and alcohol abuse and addiction
  • Pedophilia and other types of deviant sexual behavior
  • Homosexuality*
  • Cross dressing
  • Compulsive nail biting
  • Gambling
  • Smoking
  • Violent behavior
  • Anger problems
  • Weight loss

*It’s important to note that the vast majority of professionals in psychiatry and clinical psychology do not consider homosexuality to be a psychiatric “disorder” or “condition” that requires treatment, nor is it listed in the current edition of the DSM (Diagnostic and Statistical Manual of Mental Disorders).  However, because some cultures, religions, and other individuals or groups consider it to be sinful or unacceptable, aversion therapy was often used in an attempt to inhibit or eliminate homosexual urges or desires and “convert” the person to a heterosexual sexual orientation and lifestyle.  Today, the use of aversion therapy in an attempt to treat homosexuality is considered an ethical violation by both the American Psychiatric Association and the American Psychological Association.

Prior to Aversion Therapy

Due to the highly unpleasant potential effects of the various stimuli used in aversion therapy it’s important that the therapist makes sure certain things take place before therapy begins.  These include:

  • Having the client undergo a medical exam (or obtain medical clearance from the client’s physician if currently under medical care) in order to ensure that the type of stimulus being used is safe for the client. For example, the use of electrical shocks could be very dangerous for someone who has a heart condition, while someone with a gastrointestinal condition may not be an appropriate candidate for certain types of chemical aversion therapy.
  • Educating the client regarding how treatment works and what will take place, so the client knows exactly what to expect.
  • Having the client sign a consent form stating that he or she understands the process and agrees to participate in aversion therapy.

Does Aversion Therapy Work?

Aversion therapy can be quite effective, but the degree of effectiveness depends on several factors.  One of the most important factors is whether or not therapy is followed by a program geared towards relapse prevention.  This type of follow-up can greatly increase the effectiveness of treatment.  Another factor that plays an important role is the method used in therapy.  For example, aversion therapy in which electrical shocks are used has been shown to be less effective than the use of a nausea-inducing chemical like disulfiram.  Also, its effectiveness depends on the type of behavior being modified, as aversion therapy tends to be more effective with some behaviors than others.


Over the years, aversion therapy has been widely criticized and highly controversial for many different reasons, including the following:

  • The use of unpleasant stimuli such as nausea-inducing substances or electrical shocks is unethical because they cause the individual to suffer. This is a frequent criticism of disulfiram, the drug commonly used to treat alcoholism.
  • Rigorous research supporting the effectiveness of aversion therapy is lacking. Much of the research that has been done over the years shows mixed results at best and in some cases little to no effectiveness.
  • Because aversion therapy focuses on behavior only, the motivation and other psychological factors driving the unwanted behavior is never addressed. Critics assert that this is one of the primary reasons the effectiveness of aversion therapy is short-lived, at best.  Attempting to treat a complex problem such as addiction with a strictly behavioral approach is a set up for failure (e.g. relapse) down the road.  Also, with regards to addiction treatment, if the underlying issues that led to the addiction are never addressed, even if aversion therapy eliminates a specific addiction it still leaves the person highly vulnerable to developing another addiction.
  • Aversion therapy, particularly when it involves the use of electrical shocks, causes some individuals to experience significant anxiety (or worsen already existing anxiety). Some argue that it may also contribute to or exacerbate other negative emotions, such as hostility and anger.  These responses not only hinder treatment, they also suggest that this approach to treatment can end up doing more harm than good in cases.
  • Aversion therapy using electrical shocks or some forms of chemical stimuli can be dangerous for some individuals, particularly those with medical issues (particularly a medical issue that hasn’t been diagnosed) such as a heart condition or seizure disorder.
  • The use of painful stimuli such as electric shocks is often associated with punishment or even torture. The potential harmful psychological impact of that association should be seriously considered, and is another reason why the use of certain types of stimuli in aversion therapy – or any overt stimuli – is considered highly unethical by many.
  • Aversion therapy can be easily misused.
  • Some mental health professionals argue that once the use of the unpleasant stimulus is stopped, the individual can easily start engaging in the unwanted behavior again. Ongoing use of the noxious stimulus is unrealistic and impractical in many, if not most, cases.
  • Some argue that the use of use of some types of unpleasant stimuli in aversion therapy is nothing short of cruel and abusive.
  • In some instances, the use of aversion therapy can be traumatic for the individual. This is one of the reasons for the controversy surrounding the use of conversion therapy to “treat” homosexuality by religious and other groups.  Many who were treated were unduly traumatized, and some became seriously depressed and suicidal.
  • By using aversion therapy to treat homosexuality, it perpetuates the homophobic belief that being gay or lesbian constitutes a psychological disorder. By doing this, it inadvertently contributes to the hate and discrimination that many homosexual individuals face on a regular basis.
  • Many professionals regard aversion therapy as an acceptable form of treatment only if the client is administering the negative stimulus.
  • Children subjected to aversion therapy have no say in the matter, as their parents are the ones signing the consent form. Younger children may be unnecessarily traumatized by what they perceive to be punishment rather than help in the form of treatment. Concerns about the use of aversion therapy on children – particularly sexually deviant youth who end up forced into treatment that may include aversion therapy – has led to much debate and increased regulations with regards to the use of this treatment on minors.

Although aversion therapy has met with a lot of criticism and controversy over the years, it is still widely used today – especially in addiction treatment and several other types of behavior modification.  It’s an effective form of treatment for many people, and as such, shouldn’t be discounted too quickly.

If you’re interested in aversion therapy it’s important to work with a licensed medical or mental health professional who has the appropriate training and experience in this treatment approach.  Once you find a qualified professional (or treatment program), talk to them about your treatment goals and concerns to determine if this is a suitable approach for you.

If you do decide to pursue aversion therapy, talk to your physician prior to starting treatment – particularly if it will involve the use of a chemical stimulus or electric shocks.  Your health and safety are top priorities, and aversion therapy is only one of several treatment options available.  Also, if you’re considering aversion therapy to treat an addiction, make sure your treatment is combined with a relapse prevention program to help ensure your long-term success.

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