Characteristics

• Definition :

  a disorder where the individual takes a substance or engages in behaviour that’s pleasurable in the short term but eventually becomes compulsive with harmful consequence. It is marked by psychological dependance, tolerance and withdrawal
• Physical dependency:

  • occurs with long term use of a drug
  • need to take it to feel ‘normal’
  • demonstrated by presence of unpleasant physical symptoms (withdrawal syndrome)
• Psychological dependency:

  • when a drug becomes a central part of an individual’s thoughts and emotion
  • belief or mental drive that the drug is needed
  • craving, intense desire to repeat, is associated
  • unable to cope without and desire to use it again and takes over thinking completely
  • leads to habit
• Tolerance:

  • response to a drug is reduced from repetitive exposure
  • greater doses needed to produce same effect
  • enzymes responsible for metabolising do so more efficiently over time, making effect weaker
  • prolonged use leads to change in receptor density reducing response to normal dose of drug
  • learned tolerance - learned to function normally when under influence so have to take more
• Withdrawal syndrome:

  • unpleasant physical ( headache, nausea, sweats) and psychological (depression, anxiety, craving) symptoms when substance isn’t in their system
  • can only occur if a tolerance has built