chapter 22

• Substance misuse


  Substance use which results in some adverse consequences that are not recurrent
• Substance abuse


  A maladaptive pattern of substance use that manifests recurrently and has significant negative consequences
• Substance dependence


  A cluster of cognitive, behavioural and physiological symptoms (including tolerance and withdrawal) indicating that a person compulsively continues to use a substance despite significant substance-related problems
• Substance use disorders


  • Occur on a continuum of problem severity
  • Range from non-problematic (recreational) use, through misuse, to substance abuse and, finally, substance dependence
• Addiction


  A primary, chronic disease of brain reward, motivation, memory and related circuitry. Involves craving, an inability to abstain, reduced ability to recognise problems in behaviour and relationships and a problematic emotional response.
• Factors contributing to substance use disorders


  • Intrapersonal factors (biological, psychological)
  • Interpersonal factors (peer influence, social learning, disruption in social support)
  • Environmental factors (culture of drug use, availability of alcohol)
• Genetic inheritance accounts for about 50 per cent of the likelihood of an individual developing an addiction
• Interventions for substance use disorders

  • Prevention
  • Brief interventions
  • Specialised substance-abuse treatment
• The more severe the problem, the less likely it is that a person will be able to return to non-problematic use. For such individuals, the primary goal of treatment should be abstinence.
• The less severe the problem, the more likely it is that the person will be able to maintain non-problematic use. For these individuals, a goal of treatment could be controlled use.
• Drug dependence may involve physical or psychological dependence (or both)
• Physical dependence


  The person must maintain a certain level of drug in their bloodstream in order to function effectively and to avoid withdrawal symptoms
• Psychological dependence


  Users crave the positive feelings associated with using the drug
• Cross-dependence


  People develop a dependency on a drug that was initially used to relieve the withdrawal symptoms experienced when stopping another drug
• Drug tolerance


  The need to consume increasing amounts of a drug to experience the desired effect
• Metabolic tolerance


  Arises from the liver breaking down psychoactive drugs into usable derivatives or waste matter for eventual cleansing from the body
• Pharmacodynamic tolerance


  Derives from cellular adaptation that occurs with repeated use of a psychoactive agent
• Cross-tolerance


  A person has a reduced response to a drug because of previous exposure to another drug in the same family
• Numerous theories exist to explain the causes of substance use disorders
• Aetiology


  The study of the causes of disorders and diseases
• No single cause has been able to explain fully the development of substance use disorders, and it is now widely recognised that substance use disorders have multiple causes
• Risk factors


  Behaviours or environmental factors that increase susceptibility to a specific risk
• Protective factors


  Provide adolescents with the resilience to withstand the pressures of living in a risky environment
• As the number of risk factors increases, the risk of an individual developing a substance use disorder also increases
• The risk of developing a substance use disorder is mediated by protective factors that provide adolescents with the resilience to withstand the pressures of living in a risky environment
• Levels of factors implicated in the development of substance use disorders


  • Individual
  • Interpersonal
  • Environmental
• Biological factors


  • Genetic predisposition, reinforcement, neuro-adaptation
• Psychological factors


  • Personality traits, psychiatric problems, protective psychological characteristics
• Family factors


  • Family dysfunction, attachment and control aspects of parent-adolescent relationship
• Peer factors


  • Peer-related variables like hanging out with drug-using friends, peer pressure
• Mainstream institutions


  • Attachment to schools, religious organisations, educational achievement
• Social factors


  • Exposure to substance use/abuse in community, degree of acceptance or approval within community
• Cultural and economic factors


  • Stressors faced by ethnic minorities, poverty, informal economy around substance production and distribution
• Occupational factors


  • Dop system in farming, living conditions of miners
• The mining industry has also contributed to high levels of alcohol misuse
• Various features of miners' lifestyles encouraged alcohol misuse, especially the living conditions
• Many migrant miners live in same-sex hostels where the only place to socialise is the local liquor outlet
• Apart from the direct consequences of the alcohol abuse, this situation creates a high-risk environment for the transmission of HIV
• It is now widely recognised that substance use disorders have multiple causes; it is thus helpful to take a risk and resilience approach to understanding the aetiology of these disorders
• As the number of risk factors increases, the risk of an individual developing a substance use disorder also increases; however, the risk of developing a substance use disorder is also mediated by protective factors