Biological Explanation - Dopamine

Question 1

Mesolimbic pathways

Answer 1

Reward pathway
Consist of: ventral tegmental area - release dopamine when accomplished tasks (eating, finishing work)
Nucleus accumbens - pleasure it felt when it present of dopamine

Negative addictive acts also activate this system

Joshua et al - dopamine level up in participants during gambling task whether or not win

Lead to salience - addiction becomes hobby

Question 2

Tolerance + withdrawal

Answer 2

When exposed to drug - brain train to regain equilibrium to remain normal function - neuroadaptation (brain develop more receptors)
-if use repeatedly presence of drugs becomes the norm = changes in brain considered normal

Volkow et al - cocaine user has reduced D2 dopamine receptor + less dopamine released

If no drugs = brain not in equilibrium
-cause withdrawal effect - want to take drugs to go back to normal - take a long time for brain to adapt to no drug
-no take for pleasure, take for avoid withdrawal

Question 3

Role of frontal cortex

Answer 3

Volkow et al - excess dopamine release cause abnormalities in frontal cortex, change attention ability - pay more attention to stimuli associated with addiction

Robinson and Berridge - addict feel compelled to do addiction even when no pleasure - explain relapse - instinct to carry out addiction

Question 4

Evaluation - causal relationship

Answer 4

Can explain how individual progressively become addicted - develops tolerance + withdrawal

Explain relapse - by brain abnormalities

Allow for therapies to be developed - drugs

Question 5

Contradicting evidence

Answer 5

Stokes et al - no significant change in dopamine lvl in participant who took cannabis
-not as credible, may be other variables are problem (environment or role of gene)

Also does not explain how addiction is started

Question 6

Ignore individual difference

Answer 6

Does not explain why some people more likely to be addicted or not
-if dopamine only explanation = everyone react same way to drugs

A1 variant of DRD2 gene - link with D2 dopamine receptor
-those with lower activity less receptor = less stimulated - more likely to indulge more in addiction since more tolerant