Biological explanations of addiction 2013

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Biological explanations of addiction 2013

  1. 1. Biological, Cognitive and Learningapproaches to explaining initiation,maintenance and relapse, and theirapplications to smoking and gamblingAddictive Behaviour
  2. 2. DiscussionAddictionActivities associated with addictionWho is an addict?Are addictions always harmful?Celebrity storiesIn small groupscomplete thediscussion on the A3sheet in front of you
  3. 3. Initiation Maintenance RelapseAddictionA repetitive habit pattern thatincreases the risk of diseaseand/or associated personal andsocial problemsOften experiencedsubjectively as a „loss ofcontrol‟.The behaviour continuesdespite attempts to abstainor moderate use
  4. 4. Biological ExplanationIn groups identify key words that youassociate with the biological approachto PsychologyHow can we apply these terms toaddictive behaviour?i) Genetic explanationii) Disease model
  5. 5. According to the BiologicalApproach• Addiction is a specific diagnosis (youare either an addict or you are not – youcan‟t be slightly an addict)• Addiction is an illness• The problem lies within the individual• The addiction is irreversible• There is an emphasis on treatmentA01
  6. 6. Biological Approach toAddiction (Initiation)Initiation: How the behaviour gets startedThe Biological approach suggests that• a person may be most susceptible to addiction duringthe initiation phase, because they have a predisposedbiological vulnerability.• The initiation of addiction may therefore be viewed asbeing due to a genetic vulnerability which could betriggered by environmental stressors (i.e., diathesis-stress). However, it is likely to be an environmentaltrigger that initiates an addictionA01
  7. 7. Genetic Explanation(Initiation - smoking)Researchers often carry out family studies toinvestigate the possibility of genetictransmission of addictive behaviour.- Family studies of addictions have shown highrates amongst relativesA01Shields (1962) looked at 42 MZ twin pairs who had beenreared apart. They were chosen to try to separate theeffects of genetics from family influence (separatenature from nurture).Only 9/42 pairs were discordant (what does this mean?)Suggesting there might be an inherited component tosmoking addiction A02
  8. 8. Genetic Explanation(Initiation - smoking)• Maes et al (1999) studied 1412 MZ and DZ twinpairs aged 8-16 and found a significant geneticinfluence in the use of tobacco, alcohol and “other”drugs.• Kendler et al (1999) estimated heritability ofnicotine dependence to be between 60-70%.These pieces of research show a wealth ofevidence from twin studies to demonstrate thatthere is a genetic component to addictivebehavioursA02How can we link the geneticexplanations to explain why somepeople are more resistant totreatment?
  9. 9. However… can you think of any better explanationsthat genetics for the initiation of smoking?Merikangas et al…Impossible to separate out the effects of genetics andenvironmental influence (behaviour could be explainedby Social Learning Theory)A02But…could the link with addiction and genetics be indirect?Jang et al (2000), completed a study with over 300 DZ twinswhich looked at the relationship between alcohol use andpersonality.The study found a connection between genetics and anti-socialpersonality characteristics (including attention-seeking andviolence) and between these characteristics and alcoholismA02
  10. 10. Nature NurtureThis means that the Biological approach should not be used in isolation of theother approaches when explaining addictive behaviour.A02
  11. 11. A02Genetic ExplanationQ. Individual Differences?A.Diathesis-stress model explains that anindividual has a biological predisposition but anenvironmental trigger is required for thebehaviour to be exhibited- Basically some people are more vulnerable todevelop an addiction because of their genesGenetics cannot be the only cause of addictionNo research study into the genetic component ofaddictive behaviour has demonstrated 100% heritabilityin any addictive behaviour and therefore it can beconcluded that…Genetic factors cannot possibly be solely responsiblefor the development of addictive behaviours
  12. 12. Maintenance: what keeps the behaviour goingThere is genetic evidence which indicates that some people are morevulnerable than others to being dependent on substances such asnicotine and these people would therefore be more likely to maintaintheir “habit” and so remain dependent (it would also make them morelikely to relapse).However, biological predispositions are less likely to have an effectduring the maintenance of an addiction.The biological approach also suggests that neurobiological factors mayexplain the maintenance of addiction, for example, maintenance canoccur because taking an addictive substance such as nicotine, alcoholor cocaine can stimulate the pleasure and reward sites in the brain(such as the mesocorticolimbic dopamine pathway – MDP) and theperson therefore seeks out these substances so that they can continueto stimulate these pleasure areas in the brain.
  13. 13. Relapse: what makes the behaviour recur after ithas previously stoppedThis is explained by the biological approach as theindividual wanting to satisfy any physiological cravings(caused by activity in the caudomedial orbitofrontalcortex) or to stop any unpleasant withdrawalsymptoms.Mesocorticolimbic dopaminepathway is involved in pleasure +reinforcement
  14. 14. A study to support Maintenanceand RelapseSmall et al (2001)Chocolate eaten by participants = they rated it as pleasurable = brainimaging showed the MDP was being activatedWhen p‟s desired chocolate again = imaging showed the CaudomedialOrbitofrontal Cortex was activated (this brain centre is implicated inthe physical craving)So therefore the p‟s eat chocolate to ease the craving = this is thenrated pleasurable = activates MDPThe cycle continues.... and a chocoholic is born! This is how maintenanceand relapse of an addiction can be explained by the Biologicalapproach.* Eating chocolate may also cause the secretion of endorphins (pleasurechemicals through EOS
  15. 15. Genetic Explanation - MDP(Maintenance & Relapse)• The neurotransmitter most commonly implicated inaddictive behaviours is dopamine.• In normal dopamine activity, cells in the mesolimbicdopamine system are spontaneously active, releasingsmall amounts of dopamine which maintains relativelystable mood states. This enables us to maintain abalance, between our reward reinforcement system(MDP) and our control system which tells us thatwe‟ve had enough (so that we don‟t become addicted).A01How can we link this to smoking behaviour?
  16. 16. Genetic Explanation - MDP(Maintenance & Relapse)• Supporting research by Altman et al (1996) foundthat nicotine affects the nervous system byincreasing dopamine levels• Liebman and Cooper (1989) suggest that people whoare susceptible to addictions might have inherited amore sensitive mesolimbic dopamine pathway.• Caine et al (2007) found that mice engineered tolack a particular dopamine receptor do not develop ataste for the drug cocaine (something both humansand mice find highly addictive).A02
  17. 17. Genetic Explanation - EOS(Maintenance & Relapse)• There is increasing evidence to suggest that thebrain‟s opioid system may also play an important rolein addiction. Opioid neurotransmitters in the braininclude enkephalin and the endorphins. The opioidsystems are activated during states of pleasure.The EOS can be directly stimulated by addictive drugssuch as heroin, alcohol and nicotine.A01Maintenance: The person therefore desires the substance again and again inorder to feel the pleasure created by the secretion of chemicals in theEOS.Relapse: When the person does not take in the addictive substance theystill desire the pleasurable feelings associated with the substance andtherefore particularly in times of environmental stressHow can we link this to smoking behaviour?
  18. 18. Genetic Explanation – EOS(Maintenance & Relapse)• Calvert (2009) reported that smokers simply showncigarette packets experienced strong activation inspecific areas of the brain (e.g., ventral striatum – anarea well documented to be the site of rewardingfeeling)What is happening to the addict here?A02• O’Malley et al (1999) There is evidence which showsthat long-term tobacco smoking disrupts the opioidsystemThe area is associated with pleasure, nicotine affectsthis area providing pleasure, individual enjoys thefeeling, wants to repeat (maintenance) once the feelingends on a long term basis the memory of it remains(relapse)
  19. 19. Genetic ExplanationIDEA‟s /A03Approaches:Biological – empirical,objective andmeasureableDebates:Determinism Vs. Free willNomothetic Vs.IdiographicIssues:Biological reductionismEthics:Human (social sensitivity?)A03- Scientific measurements
  20. 20. Gambling• There is some confusion about termsused to describe addictive gambling.Pathological gambling is the term used todescribe a diagnosable psychiatricbehaviour.Problem gambling is the term used todescribe mild to moderate problemsassociated with gambling and as a generaloverarching term for all levels ofpotentially harmful gambling behaviours.• Gambling usually starts in adolescencefor men and later in adulthood forwomen• It is often a gradual process withindividuals progressing from social tofrequent, problem and finallypathological gambling.
  21. 21. Biological Approach toAddiction (Initiation)Initiation: How the behaviour gets startedThe Biological approach suggests that a personmay be most susceptible to addiction during theinitiation phase, because they have a predisposedbiological vulnerability. The initiation of addictionmay therefore be viewed as being due to agenetic vulnerability which could be triggered byenvironmental stressors (i.e., diathesis- stress).A01
  22. 22. Genetic Explanation(Initiation - Gambling)There is evidence that gambling runs in families.Twin studies support the idea of geneticvulnerability to pathological gambling - Shah etal (2005) conducted a twin study and foundevidence of genetic transmission of gambling inadult men.A01Comings et al (2001) suggested the possibility that thegenetic process involves the genes controlling the activityof the brain neurotransmitters dopamine, serotonin andnorepinephrine.A02
  23. 23. Genetic Explanation(Initiation - Gambling)Black et al (2006) also found that first-degree relatives ofpathological gamblers were more likely to suffer from pathologicalgambling than were more distant relatives, thus demonstrating astrong genetic link.Slutske et al (2000) found that 64% of the variation in risk forpathological gambling could be accounted for by genetic factorsalone. Familial environmental factors were less significant in theircontribution to gambling behaviour.Eisen et al (2001) using twin studies found a correlation betweenheredity and both problem gambling and alcoholism; suggestinggenetic factors may play a part in addictive behaviours generally.A02A03?
  24. 24. However… can you think of any betterexplanations that genetics for the initiation ofgambling?Financialreasons?Behavioural?Thrill?Interest?
  25. 25. Nature NurtureThis means that the Biological approach should not be used in isolation of theother approaches when explaining addictive behaviour.
  26. 26. A02Genetic ExplanationQ. Individual Differences?A.Diathesis-stress model explains that anindividual has a biological predisposition but anenvironmental trigger is required for thebehaviour to be exhibited- Basically some people are more vulnerable todevelop an addiction because of their genesGenetics cannot be the only cause of addictionNo research study into the genetic component ofaddictive behaviour has demonstrated 100% heritabilityin any addictive behaviour and therefore it can beconcluded that…Genetic factors cannot possibly be solely responsiblefor the development of addictive behaviours
  27. 27. Genetic Explanation - MDP(Maintenance & Relapse)• The neurotransmitter most commonly implicated inaddictive behaviours is dopamine.• In normal dopamine activity, cells in the mesolimbicdopamine system are spontaneously active, releasingsmall amounts of dopamine which maintains relativelystable mood states. This enables us to maintain abalance, between our reward reinforcement system(MDP) and our control system which tells us thatwe‟ve had enough (so that we don‟t become addicted).A01How can we link this to gamblingbehaviour?
  28. 28. Genetic Explanation - MDP(Maintenance & Relapse)A01One of the factors that seems to motivategamblers is the „high‟ or „buzz‟ they experiencewhen they seem close to winning. It has been foundthat certain neurotransmitter levels rise ingamblers after a winning streak.Raised levels of dopamine and noradrenaline havebeen found in people after episodes of gamblingand, in pathological gamblers, they have been foundin the anticipatory stage before the gamblingactually begins.
  29. 29. Genetic Explanation - MDP(Maintenance & Relapse)Meyer et al (2004) compared a group of problemgamblers while they were engaged in gambling andduring a control condition when they were playing cards,but not for money. They found increased secretion ofcortisol and increased heat rate in the gamblingcondition compared to the control condition.This provides evidence of a link between gambling andan individuals‟ hormone secretion, i.e., a link betweenaddictive gambling and a biological reaction.A02
  30. 30. Genetic Explanation - MDP(Maintenance & Relapse)• Roy et al (2004) found higher levels ofnorepinephrine levels in chronic blackjack gamblersand higher levels of dopamine in chronic casinogamblersThis suggests that biological neuroendocrinedisturbances can account for dependency.• Gross et al (2009) found that dopamine agonistsused to treat Parkinson‟s disease were turning 10% ofpatients into pathological gamblers.This suggests that dopamine is linked to gamblingdependency and so supports the biological explanationA02
  31. 31. Genetic Explanation - MDP(Maintenance & Relapse)How can we apply this informationpositively?The fact that dopamine is linked to dependency may lead to themanufacture of drugs acting upon dopamine production, which could reducenot only gambling dependency, but other forms of addictive behaviour too.A02Kim and Grant (2001) found that the drug naltrexone (which actsupon dopamine production) was successful in reducing compulsionsto gamble. This again adds support to the biological explanation ofaddictions, but also shows how the biological approach can lead toeffective practical applications.Paul (2008) reports that 20% of teenage gambling addictscontemplate suicide, demonstrating the pressing need for validexplanations of the condition in order for effective treatments tobe developed.
  32. 32. Approaches: Issues:Debates:Also, don’t forget..AO3..How Science Works.......Be critical

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