What is Addiction? (AQA A-Level Psychology): Revision Notes
What is Addiction?
Understanding addiction as a disorder
Addiction represents a complex disorder where individuals engage in substance use or behaviours that initially provide pleasure but progressively become compulsive despite causing harm. This condition is characterised by several interconnected features: physical and psychological dependence, tolerance development, and withdrawal symptoms.
The term addiction gained official recognition in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) in 2013. However, this classification as a mental disorder has raised concerns among some psychologists about potential stigma, which may discourage individuals from seeking necessary treatment.
Core components of addiction
Physical and psychological dependence
Addiction involves two distinct yet often overlapping forms of dependence that work together to maintain addictive behaviours.
Physical dependence occurs when the body adapts to regular drug use, creating a biological need for the substance. This adaptation becomes evident only when the person attempts to reduce or stop their drug use, as the body struggles to function normally without it. Physical dependence is confirmed by the emergence of withdrawal symptoms when the substance is discontinued.
Physical dependence represents a biological adaptation where the body's normal functioning becomes dependent on the presence of the substance. This is why withdrawal symptoms occur - the body is trying to readjust to functioning without the drug.
Psychological dependence refers to the mental compulsion to continue using a substance due to its rewarding effects. This may involve seeking increased pleasure or relief from discomfort. The reward system becomes so reliable that drug use transforms into an automatic habit, persisting even when the person recognises the harmful consequences. This psychological component often drives continued use long after physical dependence has been addressed.
Tolerance development
Tolerance describes the phenomenon where an individual's response to a given amount of a substance diminishes over time. This reduction in sensitivity means progressively larger doses are required to achieve the same behavioural or psychological effects that were previously obtained with smaller amounts.
Behavioural Tolerance Example:
People with alcohol addiction often develop strategies like walking more carefully when intoxicated to avoid falling, effectively masking some of the substance's impairing effects. This learned compensation allows them to function despite the drug's presence in their system.
Cross-tolerance represents a particularly important concept where developing tolerance to one type of drug reduces sensitivity to chemically similar substances.
Cross-Tolerance in Practice:
A classic example involves alcohol and benzodiazepines - individuals who have developed tolerance to alcohol's sedating effects require higher doses of anaesthetics during surgical procedures. This cross-tolerance can be therapeutically useful, as benzodiazepines are sometimes prescribed to individuals withdrawing from alcohol to help manage withdrawal symptoms.
Withdrawal syndrome
Withdrawal syndrome encompasses the collection of physical and psychological symptoms that emerge when an addicted person stops or significantly reduces their substance use. These symptoms typically represent the opposite of the effects produced by the drug itself, indicating that physical dependence has developed.
Nicotine Withdrawal Example:
Nicotine withdrawal commonly includes irritability, anxiety, restlessness, increased appetite, and weight gain - effects that contrast sharply with nicotine's usual appetite-suppressing and calming properties.
Once physical dependence is established, individuals experience withdrawal symptoms whenever they cannot access their substance of choice. This creates a powerful motivation to continue using, as taking the drug becomes a means of avoiding unpleasant withdrawal effects. This avoidance behaviour represents an additional form of psychological dependence, beyond the original reward-seeking motivation.
Key Points to Remember:
- Addiction involves compulsive substance use or behaviour that continues despite harmful consequences
- Physical dependence creates bodily adaptation requiring the substance to function normally
- Psychological dependence stems from the rewarding effects that make drug use feel necessary
- Tolerance means needing increasingly larger amounts to achieve the same effects
- Withdrawal symptoms are typically opposite to the drug's usual effects and drive continued use