describing addiction

• physical dependence


  a change in bodily state as a result of habitual substance use/behaviour

  a consequence of physical dependence may be withdrawal symptoms when the substance is not taken e.g., headaches following abstinence from nicotine

  other physical withdrawal symptoms include sweating, nausea, loss of energy

  it is only possible to establish a physical dependence when abstinence occurs
• psychological dependence


  feelings of an inability to cope with everyday life without a particular substance such as alcohol - it may also feel as though it is required in order to maintain a certain mood

  abstinence can cause consequences such as anxiety, irritability, depression and cravings - resulting in continuous use until it becomes habit despite harmful consequences

  psychological dependence can occur in the absence of physical dependence, in which 'true' withdrawal symptoms will not be experiences
• tolerance


  refers to when there is a reduction in an addicts response to their substance, requiring an increased amount to achieve the same effect

  this is due to homeostasis, an equilibrium which our body maintains whenever possible - digesting a substance such as alcohol disrupts homeostasis, with regular consumption/exposure leads to the brain readjusting what it considers to be normal levels of alcohol for homeostasis
• behavioural tolerance


  when an individual learns to adjust their behaviour to compensate for the effects of a drug e.g., slow talking to mask slurred speech
• cross-tolerance


  when tolerance of one drug reduces sensitivity to another drug e.g., tolerance to sleep inducing effects of alcohol may mean higher doses of anaesthetic will be needed in surgery
• withdrawal syndrome


  this refers to a set of symptoms that arise when an addicted person stops or reduces their substance use, including nausea, tremors, anxiety and agitation

  symptoms are often the opposite of ones created by the substance - nicotine reduces anxiety and abstinence may cause anxiety

  this acts as motivation for continued use and they are an indication of dependence