Genetic Factors

• Genetic Vulnerability


  All addictions are the result of an interaction between genetics and environmental triggers
• Dopamine


  Spikes when an individual experiences something pleasurable - result in the feeling of well-being
• Candidate genes


  May inherit which provide them with a predisposition towards developing addiction
• DRD2 Gene


  Addiction to; nicotine, alcohol and cocaine

  
  

  Low levels of D2 receptors in the brain means that fewer dopamine molecules can bind to these receptors - addicts require more of the substance to feel the positive effects of dopamine
• CYP2A6


  Reduces the likelihood of devolving an addiction

  
  

  Lower levels of this enzyme leads to slower rates of nicotine breakdown, reducing the concentration of nicotine metabolites within the brain's synapses
• Pianezza et al (1998)


  Found abnormal gene expression of the gene coding for the CYP2A6 enzyme in non addicts
• Kendler and Prescott (AO1)


  Conducted a study on nearly 2000 twins to investigate the link between genetic concordance and cocaine use, abuse and dependency
• Kendler and Prescott findings


  Monozygotic twins are significantly more likely to abuse or be dependant upon cocaine than dizygotic twins
• Evaluation of genetics as a risk factor - Research (AO3)


  No studies with 100% concordance rates - genetics provide a vulnerability to developing an addiction

  
  

  Role of the environment - stress, family and personality may affect the predisposition to addiction
• Evaluation of genetics as a risk factor - Gender (AO3)


  McGue points out that few adoption studies that only a few adoption studies have reported a significant correlation between female adoptees and their biological parents for addiction

  
  

  Genetic factors may be less important for women than men
• Evaluation of genetics as a risk factor - Twins a participants (AO3)


  MZ twins are more likely to be treated militarily by their parent and peers than DZ twins- concordance rates could be strongly influenced by upbringing rather than genetic similarities