Tolerance and withdrawal

• What happens to dopamine receptors with prolonged drug use?

  • with continued exposure to addictive substances or behaviours, the dopamine receptors become less sensitive

  • this results in tolerance, meaning the person needs higher amounts of the drug/behaviour to achieve the same pleasurable effect
• What research supports the link between addiction and dopamine receptor changes?

  • Volkow et Al (1997) found that drug addicts have a decrease in D2 receptors and dopamine release, making them less responsive to normal pleasure
• How does addiction shift from pleasure-seeking to withdrawal avoidance?

  • Initially, addiction is about seeking pleasure, but over time, the brain depends on the drug/behaviour to maintain normal dopamine function

  • stopping causes unpleasant withdrawal symptoms, making the behaviour about avoiding discomfort rather than feeling good

  • examples of withdrawal symptoms: physical - sweating, shaking, nausea, psychological - anxiety, depression, cravings