Addiction: clinical characteristics, the biological explanation (genes and the role of dopamine) and the psychological explanation (learning through reinforcement), and treatments including drug therapy and behavioural approaches such as aversion therapy.

What this dot point is asking

OCR wants you to describe the clinical characteristics of addiction, explain it from a biological view (genes and dopamine) and a psychological view (learning through reinforcement), and evaluate treatments: drug therapy (biological) and behavioural approaches such as aversion therapy (psychological).

Clinical characteristics of addiction

The biological explanation

The biological explanation says addiction has physical causes.

• Genes. Addiction can run in families, and twin and adoption studies suggest people may inherit a predisposition (for example, differences in how they respond to a substance), so they are more likely to become addicted.
• Dopamine and the reward system. Addictive substances and behaviours flood the brain's reward system with the neurotransmitter dopamine, producing pleasure. The brain learns to repeat whatever caused this, and over time needs the substance to feel normal, driving craving and tolerance.

The psychological explanation

The psychological explanation says addiction is learned, mainly through conditioning:

• Positive reinforcement (operant conditioning). The substance or behaviour produces a pleasant effect (a high, relaxation, excitement), which rewards the behaviour, so it is repeated.
• Negative reinforcement. Once dependent, the person takes the substance to avoid unpleasant withdrawal symptoms; removing something unpleasant also strengthens the habit.
• Social learning. People may start by observing and imitating role models (friends, family, celebrities) they see using and being rewarded.

Treatments for addiction

Drug therapy (biological). Medication can reduce cravings or block the pleasant effect of a substance, or provide a safer substitute (for example, nicotine replacement for smoking). Strengths: can ease withdrawal, helping people quit, and acts on the biological cause. Weaknesses: treats the symptoms not the underlying habit, can have side effects, and the addiction may return when the drug stops.

Aversion therapy (psychological/behavioural). Based on classical conditioning, it makes the person associate the substance with something unpleasant. For example, a drug may cause nausea whenever alcohol is drunk; after repeated pairings, alcohol becomes linked to feeling sick, creating an aversion so the person avoids it. Strengths: directly targets the learned association that maintains the addiction. Weaknesses: the effect may not last outside the clinic, it raises ethical concerns (deliberately causing discomfort), and it treats the behaviour without addressing why the person became addicted.

Evaluating the explanations and treatments

The biological explanation is scientific and explains tolerance and craving through dopamine and genetics, but it is reductionist and cannot easily explain why people exposed to the same substance differ. The psychological explanation explains how addiction is learned and maintained (and why social settings matter), but underplays biology. The treatments mirror this: drug therapy eases the physical side but not the habit, while aversion therapy tackles the learned association but may not last and is ethically questionable. As with depression, addiction usually has multiple causes, so the most effective approaches often combine biological and psychological treatments with social support.

Try this

Q1. Name the neurotransmitter central to the brain's reward system in addiction. [1 mark]

• Cue. Dopamine.

Q2. Explain the difference between positive and negative reinforcement in addiction. [2 marks]

• Cue. Positive reinforcement is taking the substance for its pleasant effect; negative reinforcement is taking it to remove unpleasant withdrawal.

Q3. On which type of conditioning is aversion therapy based? [1 mark]

• Cue. Classical conditioning.