Interactionist approach to schizophrenia

• Interactionist approach

  = An approach that acknowledges that there are biological, psychological and social factors in the development of schizophrenia.

  • Biological factors include genetic vulnerability and neurochemical and neurological abnormality.
  • Psychological factors include stress, resulting from life events.
  • Social factors include poor quality interactions in the family.
• Diathesis stress model

  = An interactionist approach to explaining behaviour. Both a vulnerability to schizophrenia and a stress trigger are necessary in order to develop schizophrenia.

  • One or more underlying factors make a person particularly vulnerable to developing schizophrenia but the onset is triggered by stress.
• Meehl's model

  • If the person does not have the schizophrenic gene then no amount of stress would lead to schizophrenia.
  • However carriers of the gene, chronic stress through childhood and adolescence and the presence of a schizophrenic mother could result in the development of the disorder
• Modern understanding of diathesis

  • Now clear that many genes appear to increase genetic vulnerability only slightly, there is no single schizophrenic gene= polygenic.
  • Also include a range of factors including psychological trauma so trauma also becomes the diathesis rather than the stressor.
  • Read proposed a neurodevelopmental model in which early trauma alters the developing brain and can seriously affect many aspects of the brain.
  • The hypothalamic pituitary adrenal system can become overactive making a person more vulnerable to later stress.
• Modern understanding of stress

  • Includes anything that risks triggering schizophrenia.
  • Recent research into factors triggering an episode of schizophrenia has concerned cannabis use. Cannabis is a stressor because it increases the risk of schizophrenia by up to 7 times. This may be because cannabis interferes with the dopamine system.
  • However most don't develop schizophrenia because they lack the vulnerability factors
• Treatment

  • Interactionist approach acknowledges both biological and psychological factors in schizophrenia and is therefore compatible with both biological and psychological treatments.
  • Associated with combining antipsychotic drugs and psychological therapies. (CBT)
  • In Britain it is increasingly standard to treat people diagnosed with schizophrenia with a combination of antipsychotic drugs and CBT.
• Evaluation- support for vulnerability and triggers

  • Investigated the impact of both genetic vulnerability and a psychological trigger.
  • A high genetic risk group were compared to a control group of adoptees without family history of schizophrenia.
  • Found that high levels of criticism, hostility and low levels of empathy were strongly associated with the development of schizophrenia but only in high genetic risk group.
  • Shows a combination of genetic vulnerability and family stress can lead to greatly increased risk of schizophrenia
• Evaluation- diathesis and stress are complex

  • Multiple genes in multiple combinations influence diathesis.
  • Stress also comes in many forms, including dysfunction parenting.
  • Diathesis can also be influenced by psychological factors and stress can be biological.
  • Houston, showed that childhood sexual abuse emerged as the major influence on underlying vulnerability to schizophrenia and cannabis use as the major trigger.
  • Means that there is multiple factors, both biological and psychological affecting both diathesis and stress supporting the modern understanding.
• Evaluation- real world application

  Strength= combination of biological and psychological treatments.

  • A practical application is the combination of drug treatment and psychological therapies. Studies show that combining treatments enhance their effectiveness
  • Tarrier found that participants in both medication and therapy showed lower symptoms following the trial than the medication only group, though there was no difference in hospital readmission.
  • Means there is a clear practical advantage to adopting an interactionist approach to schizophrenia in terms of superior treatment outcomes.
• Evaluation- counterpoint

  • Jarvis and Okami point out that saying that a successful treatment for mental disorder justifies a particular explanation is the logical equivalent of saying that because alcohol reduces shyness, shyness is caused by lack of alcohol. The logical error is called the treatment-causation fallacy.
  • Therefore we cant automatically assume the success of combined therapies means interactionist explanations are correct.