Edexcel Psychology for A Level Yr 2 Revision Guide

Issues around drug-taking Check it 1. Explain two issues associated with drug-taking. (4) 2. Frieda is addicted to heroin. She has not had any heroin for nine days. Explain how this might affect Frieda. (3) 3. Standard essay: Evaluate issues around drug-taking. (8) or (16) 4. I&D essay: Assess the use of psychological knowledge in society using examples from your chosen application (criminological, child or health). (16) Revision booster The terms in the specification relating to issues around drug taking are interlinked – addiction, tolerance, dependency and withdrawal – but it is important to be able to distinguish between them clearly as they will be used in exam questions and you need to provide specific answers. One a day to keep the craving at bay. ‘CA’ stands for ‘competing argument’. A strength is that addiction can be explained in terms of neural mechanisms. Repeated exposure to the effects of a drug can cause changes to brain structure and function, for example downregulation . Chronic drug-taking means a reduction in number of postsynaptic receptors available for binding with a neurotransmitter, altering synaptic transmission. This understanding of the neural mechanisms involved helps to make the causes of addiction clearer. CA Some brain mechanisms in addiction are not well understood. The mesocorticolimbic circuit (see next spread) and dopamine are key elements of addiction because of their roles in reward. But a focus on these is limited because there are other neurochemical mechanisms involved (e.g. GABA and serotonin ). Although dopamine is central, it interacts with other brain processes. A weakness is that research on rats is hard to generalise to humans. The neural mechanisms underlying tolerance, dependency, withdrawal and addiction are similar in human and rat brains, but they are not identical. In the rat park, Alexander et al . (1978) showed that the social environment affects addiction in rats. Psychological and sociocultural factors are even more critical in humans. This means we must be cautious about interpreting findings from animal studies and applying them uncritically to human addiction. Another strength is that there are controlled animal studies on tolerance. Siegel et al . (1982) injected rats with heroin every other day for 30 days, and then finally with a very large dose. 32% died, but the rest developed tolerance. Siegel (1984) also found tolerance in humans – the most frequent victims of fatal heroin intake were ‘weekend’ users who did not use the drug enough to develop tolerance. This is strong support for the key role of tolerance, in studies that cannot ethically be conducted on humans. Application: As knowledge increases, more treatments become available. Understanding physical dependency in nicotine addiction has led to effective treatments (e.g. nicotine replacement therapy to manage withdrawal). Psychological dependency is addressed by helping smokers avoid the cues they associate with the rewarding effects of nicotine. This means the research has led to ways in which the personal and social costs linked to drug- taking can be significantly reduced. I&D extra: These concepts illustrate different ways of explaining addiction. One biological explanation for heroin addiction focuses on neural mechanisms in the CNS involving reward pathways and neurotransmitters. But these interact with psychological processes (e.g. learning) and social factors that increase the risk of addiction (e.g. peer/family relationships, sources of stress). This shows how explanations in psychology can combine to provide a fuller explanation for a behaviour. 157 AO3 Evaluation