Introduction to aversion therapy

Aversion therapy is a type of behavioural therapy used to treat addictions, such as those to alcohol or nicotine. It aims to reduce or eliminate unwanted behaviours by creating negative associations with them. This therapy is particularly useful for substance addictions where individuals have developed positive links between the substance and feelings of pleasure or relief.

Basis in classical conditioning

Classical conditioning is a form of learning discovered by Ivan Pavlov, where a neutral stimulus (something that initially causes no response) is repeatedly paired with an unconditioned stimulus (something that naturally triggers a response) until the neutral stimulus alone elicits a similar response.

In aversion therapy, this process is applied to addictions by pairing the addictive substance (initially a neutral or positive stimulus) with an aversive stimulus - an unpleasant event or sensation that naturally causes discomfort. Over time, this pairing leads to the substance triggering a negative response, reducing the desire to engage with it.

Key elements of classical conditioning in aversion therapy

• Unconditioned stimulus (UCS) - A naturally aversive event, such as nausea from a drug or pain from an electric shock, which automatically produces an unconditioned response (UCR) like discomfort or pain.
• Neutral stimulus (NS) - The addictive substance (e.g., alcohol or a cigarette) before conditioning, which does not initially cause aversion.
• Conditioned stimulus (CS) - After repeated pairings, the substance alone becomes the CS, triggering a conditioned response (CR) of aversion or negative emotions.
• Conditioned response (CR) - The learned negative reaction to the substance, such as feelings of nausea or pain, which discourages its use.

This conditioning shifts the substance from being reinforcing (providing pleasure) to punishing (causing discomfort), helping individuals unlearn harmful associations.

Procedure for treating alcohol addiction

For alcohol addiction, aversion therapy often involves medical intervention to create strong negative associations. Patients who are physically dependent on alcohol may first need detoxification before starting therapy. The procedure is explained fully to the patient, who must provide informed consent. Treatment typically occurs in a hospital setting, combined with psychological counselling and social support.

Steps in alcohol aversion therapy sessions

1. Administration of aversive stimulus - Under medical supervision, the patient receives an emetic drug such as emetine by injection. This drug directly causes severe nausea and vomiting, creating a strong unpleasant physical response.
2. Pairing with alcohol - A few minutes after the drug takes effect and sickness begins, the patient is exposed to the sight, smell, and taste of their preferred alcoholic drink. They take a sip without swallowing to link the nausea directly to alcohol.
3. Repetition and duration - This pairing is repeated over around 30 to 60 minutes during each session, as vomiting and nausea intensify. Multiple sessions occur as part of a broader programme.
4. Booster sessions - To maintain the aversion, follow-up sessions may be scheduled over several months to over a year or even lifelong, reinforcing the negative association.

Through these steps, alcohol changes from improving mood and wellbeing to causing negative effects, encouraging abstinence.

Procedure for treating nicotine addiction

Aversion therapy for nicotine addiction uses a similar classical conditioning approach, but with a different aversive stimulus. Instead of an emetic drug, a mild electric shock is used, administered every time the patient takes a puff from a cigarette.

Steps in nicotine aversion therapy sessions

1. Administration of aversive stimulus - Instead of an emetic drug, a mild electric shock is used as the UCS, which naturally causes pain or discomfort (UCR).
2. Pairing with smoking - The patient takes a puff from a cigarette (initially the NS), and immediately receives the electric shock. This pairs the act of smoking with pain.
3. Repetition and conditioning - Over several pairings, the sight, smell, or act of handling a cigarette becomes the CS, leading to a CR of negative emotional response, such as aversion or anxiety.

How aversion therapy changes associations

Aversion therapy fundamentally alters the learned connections individuals have with addictive substances. Initially, substances like alcohol or nicotine are associated with positive outcomes, such as relaxation or mood enhancement, through prior experiences.

By repeatedly pairing the substance with an aversive stimulus, the therapy replaces these positive associations with negative ones. For example, alcohol shifts from being a mood booster to a source of physical illness, while cigarettes become linked to pain rather than pleasure. This unlearning process relies on the principles of classical conditioning to make the behaviour less appealing.

Long-term aspects and evaluation

• Integration with other treatments - Aversion therapy is most effective when combined with counselling and social support.
• Duration and maintenance - Booster sessions help sustain the aversion over time.