interactionist approach to SZ

• The interactionist approach also known as the biosocial approach acknowledges that there are biological, psychological and social factors in the development of SZ
• Biological factors include:

  • genetic vulnerability
  • neurochemical and neurological abnormality
• Psychological factors include:

  • stress resulting from life events
  • daily hassles
  • poor quality interactions in the family (social)
• diathesis means vulnerability and refers to a genetic predisposition to mental illness
• the diathesis-stress model says that vulnerability to SZ and a stress-trigger are necessary to develop the disorder
• one or more underlying factors make a person more vulnerable to developing SZ, but the onset is always triggered by stress
• Meehl's model (1962)


  • diathesis was originally thought to be based on a single 'schizogene' which made a person more sensitive to stress
  • if a person does not have this gene no amount of stress will lead to SZ
  • carriers of the gene who experienced chronic stress through childhood and adolescence in particular a schizophrenogenic mother, could result in development of SZ
• Modern Model, Ripke et al. (2014)


  Many genes increase genetic vulnerability to SZ, no single 'schizogene'
• Modern Model, Ingram and Luxton (2005)


  • Many factors beyond genetic are included in the modern view of diathesis like psychological trauma
  • Diathesis is seen as vulnerability not stressor
• Modern Model, Read et al. (2001)


  • Neurodevelopmental model highlights how early trauma alters the developing brain
  • For example: HPA system can become overactive, making a person more vulnerable to later stress
• Modern Model, Houston et al. (2008)


  • Stress is not just about psychological aspects in relation to parenting it also includes anything else that risks triggering SZ
• Modern Model: stress

  • Recent research into factors triggering an episode of SZ has concerned cannabis use
  • Makes a person 7 x more likely to develop SZ as it interferes with dopamine system
• Treating SZ with the interactionist model combines psychotic medication and psychological therapies
• Turkington et al (2006) points out it is possible to believe in biological causes of SZ and still practise CBT to relieve psychological symptoms
• Interactionist ideas are more common in the UK, it is standard practise in Britain to use a combination of CBT and antipsychotic drugs to treat SZ
• Tienari. et al (2004) study wanted to see if genetics play a role in how someone responds to family dynamics
• Tienari et al (2004) study sample was

  • 145 adopted children whose biological mothers had SZ
  • A control group of 158 adopted children whose biological mothers did not have SZ
• Tienari et al. (2004) Procedure:

  • Researchers assessed the adoptive family environments using interviews and psychological tests
  • They categorised the adoptive families as either “healthy” or “dysfunctional” based on the level of support, communication, and conflict within the family