Neurochemical Explanations Of Nicotine Addiction

Question 1

addiction initiation

Answer 1

smoke is inhaled

nicotine enters brain and binds to neurons in ventral tegmental area (VTA)

these neurons trigger release of dopamine in nucleus accumbens

effects the pre-frontal cortex which is responsible for decision making, explaining why addicts might choose short-term benefits (smoking) over long-term consequences (cancer)

release of dopamine produces feelings of reward & pleasure. it is this pleasure & drive to repeat the process that leads to addiction

Question 2

addiction maintenance

Answer 2

when someone goes without nicotine (e.g. when they sleep), it is metabolised

this means the smoker experiences acute withdrawal syndrome as the nicotine receptors (nAChRs) are available but not being stimulated. to avoid withdrawal, a smoker will have another cig

chronic desensitisation (from repetitive activation & deactivation of nAChRs) means a smoker must increase nicotine intake for same effect (tolerance)

this explains how nicotine addiction is maintained as the smoker now has a cig to avoid withdrawal syndrome and ‘feel normal’

Question 3

strength of brain chemistry

Answer 3

strong research evidence

McEvoy et al (1995)

studied smoking behaviour in schizophrenic patients some of which were taking haloperidol (dopamine antagonist), smoking increasing in sample. acted as a form of self-medication, attempt to achieve nicotine hit by increasing dopamine release

reinforces importance of dopamine reward system in nicotine addiction

Question 4

strength 2

Answer 4

real life applications

when the theory can be used in real life to benefit society

NRT in form of patches or inhalers has been developed to help people overcome addiction. gives a controlled amount of nicotine, allowing them to manage withdrawal whist activating dopamine reward pathway

suggests neurochemical explanation of nicotine addiction has helped society through development of successful treatments, increasing validity

Question 5

limit 1

Answer 5

too simplistic

only focuses on one neurotransmitter system (dopamine)

however, more recent research suggests a complex interaction of several systems,, such as GABA and serotonin pathways, are involved in nicotine addiction

suggests although dopamine is central to nicotine addiction, in order to get holistic understanding, we need to assess how other neurotransmitters are included

Question 6

limit 2

Answer 6

biologically reductionist

which is when a theory suggests our free choice is limited by internal, biological factors

choi et al (2003) found only 50% of people who experimented became dependent. also most adolescents who become dependent had peers who smoked or felt they were underachieving in school

suggests could be argued that crucial environmental and psychological factors (inc peer pressure, self-esteem, confidence) are in danger of being ignored by focusing on brain neurochemistry to explain addiction