Aversion therapy: what is it, and how does it work?

Felix Gussone, MD - Contributor Avatar

Reviewed by Felix Gussone, MD, Ro, 

Written by Jordan Davidson 

Felix Gussone, MD - Contributor Avatar

Reviewed by Felix Gussone, MD, Ro, 

Written by Jordan Davidson 

last updated: Jun 23, 2021

3 min read

Everyone has a habit or two they'd prefer they didn't have. Some habits are mere nuisances, while others can disrupt one’s life and impact one’s health. These undesirable behaviors can be hard to break despite the best of intentions. While looking for strategies to give up these habits, you might have come across aversion therapy. Although aversion therapy might seem like a good option if you’re desperate to give up a bad habit, newer therapies and some medications likely offer more hope.


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What is aversion therapy? 

Aversion therapy is a form of classical conditioning. It’s designed to reduce undesirable behaviors (such as drinking alcohol) by forcing your mind to associate your unwanted “bad” habits with uncomfortable or painful sensations (American Psychological Association, n.d.)

Take drinking alcohol, for example. People with alcohol use disorder feel an urge to drink partly because alcohol lights up their brain's reward center. When your brain associates something with pleasure, you're more likely to repeat it. This pleasure activation can lead to alcohol abuse in people vulnerable to alcoholism (American Psychiatric Association, 2013).

But instead of associating unwanted behaviors with pleasure, the theory behind aversive conditioning is that your brain learns those behaviors come with something unpleasant. Over time, this so-called counterconditioning is thought to work without the unpleasant stimulus, reducing the likelihood of engaging in harmful behavior. 

What does aversion therapy treat?

According to the American Society of Addiction Medicine, aversion therapy is an acceptable treatment for alcoholism and substance abuse (Frawley, 2015). Aversion therapy has also been used to treat gambling, smoking, and nail-biting. 

While aversion therapy treatment programs exist, they are not typically considered the first line of defense for tackling unwanted behaviors. For example, when it comes to gambling, cognitive-behavioral therapy (CBT) works better than aversive methods (Rizeanu, 2015).  

Because aversion therapy relies on unpleasant stimuli, treatment can be difficult to complete. Your doctor will likely recommend other therapies before suggesting aversive techniques.

How aversion therapy works 

Electrical shock and emetics, substances that induce vomiting, are two examples of aversive stimuli that are supposed to help you get rid of your habit. Aversion treatment often occurs as part of inpatient treatment programs or under the careful watch of a mental health professional. Modern use of electric shock gets delivered through electrodes placed on your forearm. For example, when used for smoking cessation, the shocks occur when you move your hand toward your mouth to smoke. Chemical aversion therapy with emetics tends to be more expensive than other therapies because it must be performed in a hospital or medical facility. Medical clearance is also needed to make sure your body is strong enough to handle the medications used for aversion therapy (Frawley, 2015). 

Aversion therapy for alcohol abuse under the supervision of a healthcare professional often uses ipecac, a syrup that causes vomiting. Treatment entails tasting and swallowing alcohol, often while looking at alcohol-related images, and then inducing vomiting with ipecac (Elkins, 2017).

In one small study at Washington University, these sessions occurred under the care of a hospital or treatment facility every other day for 10 days. After the treatment, the researchers used fMRIs to image the brains of those with alcohol abuse disorder and found significant reductions in craving-related brain activity. 69% of people in the study remained sober a year after a 10-day inpatient treatment program (Elkins, 2017).

One of the first FDA-approved drugs used to treat alcohol dependence was disulfiram. The medication causes an aversive reaction in combination with alcohol. When taken with alcohol, disulfiram causes flushing, headaches, nausea, and vomiting (Stokes, 2020). Though some practitioners still use disulfiram, randomized control trials show that the drug isn't always effective (Zindel, 2014). Some evidence suggests disulfiram may help reduce cocaine use in those with substance abuse disorder (De Sousa, 2019). 

Aversion therapy for nail-biting tends to be less extreme than the measures used for other undesirable behaviors. It must be carefully performed since nail-biting can get worse with shaming or “punishment” (Baghchechi, 2020). Rather than using electric shock or emetics, the treatment utilizes aversive therapy as part of a three-step behavior modification technique. This type of behavioral therapy includes using foul-tasting nail polish, maintaining good nail hygiene, and obstacles (like bandaids covering your fingertips) that can make it difficult to bite nails (Baghchechi, 2020). 

The use of aversion therapy has a dark history in certain communities.

Before the American Psychological Association removed homosexuality from the DSM in 1973, aversion therapy was used on queer people as a type of conversion therapy (Carr, 2019). Critics have also condemned the use of shock therapy on people with autism and intellectual disabilities (Kirkham, 2017). Today, aversion therapy is only considered acceptable if it’s consensual and not forced on a person. 

Aversion therapy can be considered used once other therapies fail. Not many people are willing to put themselves through weeks or months of electric shock or vomit-inducing medication, giving aversion therapy a high dropout rate (Costello, 1969). 

Though there are safe ways to perform aversion therapy, other research-backed therapies and medications that may be more effective and can spare you the time and discomfort of putting yourself through electric shocks or vomiting.


If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

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Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

Current version

June 23, 2021

Written by

Jordan Davidson

Fact checked by

Felix Gussone, MD

About the medical reviewer

Felix Gussone is a physician, health journalist and a Manager, Medical Content & Education at Ro.