Describing Addiction and Risk Factors

Addiction is a disorder in which a person becomes dependent on a substance (such as nicotine or alcohol) or a behaviour (such as gambling). To describe it accurately for AQA, you need four features: physical dependence, psychological dependence, tolerance and withdrawal syndrome.

These are not four names for the same thing. A person can be psychologically dependent on gambling without any physical dependence, or physically dependent on a drug they no longer even crave. Being precise about which feature you mean is what separates a Level 3 answer from a vague one.

Feature	Core idea
Physical dependence	The body has adapted; stopping causes withdrawal symptoms
Psychological dependence	A compulsion or craving; a belief you cannot cope without it
Tolerance	Needing more over time to get the same effect
Withdrawal syndrome	The symptoms that appear when a dependent person stops

Describe addiction by these four features, not by how much someone uses. Frequency of use is a clue, not the definition.

Physical dependence means the body has physically adapted to the presence of the substance. The body now treats the drug as part of its normal chemistry, so when the drug is reduced or removed, the body reacts with withdrawal symptoms. The person needs the substance simply to function normally and feel physically well.

Psychological dependence is different. It is a strong compulsion or craving to keep using, together with a belief that one cannot cope or feel normal without the substance or behaviour. The pull here is emotional and cognitive rather than bodily.

Dependence type	What has changed	Key sign
Physical	The body has adapted	Withdrawal symptoms when use stops
Psychological	Thinking and emotion	Craving and "I can't cope without it"

The two often occur together, but they do not have to. Gambling addiction, for example, is largely psychological: there is a powerful compulsion to gamble even though there is no drug for the body to adapt to.

Physical dependence = the body needs it to avoid withdrawal. Psychological dependence = the mind craves it and feels unable to cope without it.

Tolerance is a reduced response to a substance, so that the person needs more of it over time to achieve the same effect they once got from a smaller amount. It develops because the body adapts to repeated exposure.

A common mechanism is down-regulation: when a drug repeatedly floods the brain with a neurotransmitter or over-stimulates receptors, the brain compensates by reducing the number or sensitivity of those receptors. The same dose now produces a weaker effect, so the dose has to rise to match it.

Worked example — a regular drinker:

• A first-time drinker may feel strong effects from two units of alcohol.
• After months of heavy drinking, the same two units barely register.
• To feel the original effect, they now drink six or more units.

That escalation is tolerance in action, and it helps drive the increasing use seen in addiction.

Cross-tolerance is a related idea: tolerance built up to one drug can carry over to a similar drug (for example, tolerance to one depressant can reduce the effect of another). You do not need great depth on this, but naming it shows understanding.

Withdrawal syndrome is the set of unpleasant physical and psychological symptoms that appear when a dependent person stops using a substance or cuts down sharply. It is the flip side of physical dependence: because the body has adapted to the drug, removing it throws the body out of balance.

Typical withdrawal symptoms include:

• Physical: tremors, sweating, nausea, headaches, raised heart rate.
• Psychological: anxiety, irritability, low mood and intense cravings.

Withdrawal usually has two phases:

Phase	What happens
Acute phase	Intense, short-lived symptoms peaking within days of stopping
Prolonged phase	Milder symptoms (such as cravings and low mood) lasting weeks or longer

The prolonged phase matters because cravings can persist long after the acute symptoms fade, which is one reason relapse is common well into recovery.

Withdrawal symptoms are evidence of physical dependence: the body reacts because it had adapted to the substance. Cravings that continue for weeks belong to the prolonged phase.

The AQA spec names three risk factors in the development of addiction. The first is genetic vulnerability: some people inherit a predisposition that makes them more likely to become addicted if they encounter a substance.

A key candidate is genetic variation affecting the brain's dopamine system, the main reward pathway. The A1 variant of the DRD2 gene is associated with fewer dopamine (D2) receptors, which may make substance use feel more rewarding and harder to resist. Twin and family studies support a genetic component: relatives of people with addictions show a higher risk of addiction themselves, and identical twins tend to be more concordant than non-identical twins.

The crucial word is vulnerability. Inheriting these genes raises the risk; it does not make addiction certain. A person with a genetic predisposition who never encounters the substance, or whose environment protects them, may never become addicted.

Genetic vulnerability is a predisposition, not a guarantee. It works by making addiction more likely, usually through the dopamine reward system, not by forcing it to happen.

Personality is the second risk factor. Certain traits raise the likelihood of addiction, especially impulsivity (acting without weighing consequences) and sensation-seeking (seeking novel, intense experiences). Traits linked to antisocial personality disorder are also associated with higher risk.

Importantly, research does not support a single unified "addictive personality." AQA treats personality as one risk factor among several, not as a fixed personality type that dooms a person to addiction.

Social influences are the third risk factor. The social environment strongly shapes whether an addiction develops:

Social influence	How it raises risk
Peers	Peer pressure and social learning (modelling) of substance use
Family	Parental attitudes and modelling of using behaviour
Availability	Easy access to the substance makes use, and addiction, more likely
Social norms	If use is seen as normal or acceptable, it is more likely to be taken up

Social learning theory helps explain the peer and family effects: people observe and imitate substance use in others they identify with, especially when they see it being reinforced (for example, appearing to relieve stress or gain social status).

The three named risk factors are genetic vulnerability, personality and social influences. Learn all three by name, with an example of each.

You will usually be asked to evaluate these risk factors (AO3), so each point below is a developed argument, not just a fact.

Genetic vulnerability — supporting evidence, but not deterministic. Twin and family studies back a genetic component; for example, Kendler et al. (2000), using Swedish adoption data, found that adopted children of biological parents with an addiction had a raised risk of addiction themselves. However, genes are not deterministic: they create a vulnerability that still needs environmental triggers. Family studies also struggle to separate shared genes from a shared family environment, which weakens purely genetic conclusions.

Personality — a correlational problem. Evidence linking traits like impulsivity to addiction is largely correlational, so cause and effect are hard to establish. Does an impulsive personality lead to addiction, or does long-term substance use change the personality (for example, making a person more impulsive)? The direction of the relationship is unclear, and there is no evidence for a single "addictive personality."

Social influences — real but insufficient alone. Peer substance use is one of the strongest predictors of adolescent use, which supports the role of social factors. But not everyone exposed to using peers becomes addicted, so social influence alone cannot fully explain who develops an addiction.

The most defensible position is that risk factors combine. A biopsychosocial or diathesis-stress view holds that genetic vulnerability (the diathesis) interacts with personality and social context (the stressors) to determine who becomes addicted.

1. Confusing physical and psychological dependence

Physical dependence is about the body adapting and producing withdrawal when use stops. Psychological dependence is the craving and compulsion and the belief you cannot cope without it. Describing craving as "physical dependence" loses marks.

2. Confusing tolerance with withdrawal

Tolerance is needing more of the substance to get the same effect. Withdrawal is the set of symptoms that appear when you stop. They are opposite sides of adaptation, not the same thing.

3. Treating genetic vulnerability as a guarantee

Genes create a predisposition, not a certainty. Writing that someone "will become addicted because of their genes" overstates the evidence. Genetic vulnerability raises risk and interacts with the environment.

4. Claiming there is a single "addictive personality"

Research does not support one unified addictive personality. Refer instead to specific traits such as impulsivity and sensation-seeking as risk factors, and note the lack of evidence for a single personality type.

5. Listing risk factors without evaluating them

An AO3 question wants evaluation: strengths, limitations, correlation-versus-causation issues and the idea that factors combine. Simply re-describing the three risk factors answers an AO1 question, not an evaluation one.