Interactionist approach

• What is the interactionist approach to schizophrenia?

  • Sometimes known as the 'biosocial' approach acknowledges that there are biological, psychological, and social factors in the development of schizophrenia
  • Includes genetic vulnerability, neuro-chemical abnormality, stress from life events, poor quality family interactions, etc.
• What is the original diathesis-stress model?

  • Says that both a vulnerability to schizophrenia and a stress-trigger are necessary in order to develop the disorder
  • Although there are multiple underlying factors that can make someone vulnerable to schizophrenia, the onset of the condition is triggered by stress
• What is the original diathesis-stress model for schizophrenia?

  • Meehl (1962)'s model claimed diathesis (vulnerability) was entirely genetic, the result of a single 'schizogene'
  • Led to the idea of a biologically based schizotypic personality, a characteristic being sensitivity to stress
  • According to this if a person doesn't have the genetic vulnerability, then NO amount of stress would lead to schizophrenia
• What is the modern understanding of a diathesis?

  • We now know that many genes increase vulnerability for schizophrenia so there is no single 'schizogene', evidenced by Ripke et al (2014)'s findings
  • Diathesis is no longer just genetic, researchers have found that psychological trauma can act as a vulnerability rather than a stressor
  • Read et al. (2001) proposed a neuro-developmental model where early and severe trauma can change the brain - for example stress can make the hypothalamic-pituitary-adrenal system (HPA, regulates stress responses) to become overactive, which then makes the person much more vulnerable to later stress
• What is the modern understanding of stress?

  • Stress was seen as psychological in nature in particular caused by parenting, but is now seen as anything that risks triggering schizophrenia
  • Recent research has found cannabis increases the risk of schizophrenia by up to 7x because it interferes with the dopamine system
  • But most people who smoke cannabis don't develop schizophrenia due to lacking the vulnerability factors
• What does the interactionist approach recommend for treatment?

  • Compatible with both biological and psychological treatments, particularly associated with combining antipsychotic medication with therapies like CBT
  • Turkington et al. (2006) pointed out it is perfectly possible to believe in biological causes of schizophrenia and simultaneously treat patients with CBT - it is increasingly standard practice in Britain to combine biological and psychological treatments
• What is one strength of the interactionist approach?

  • Research support for vulnerability and triggers: Tienari et al. (2004) compared 145 adoptees (with schizophrenic biological mothers) to 158 low-risk adoptees
  • Family functions were assessed using the DOPAS scale which looks at communication and empathy
  • 14 overall developed schizophrenia, 11 of them being from the high-risk group which also showed signs of adoptive family stress
  • Shows that a combination of family stress and genetic vulnerability can lead to a greatly increased risk of schizophrenia
• What is another strength of the interactionist approach?

  • Real-world application: a practical application of acknowledging biological and psychological factors has been the combination of medication and therapy, evidenced for enhanced effectiveness
  • Tarrier et al. (2004) randomly allocated 315 participants to groups for medication, CBT, and a combination of both
  • Combination groups reported a larger reduction in symptoms, showing a clear practical advantage to adopting an interactionist approach to schizophrenia
• What is one limitation of the interactionist explanation?

  • Treatment-causation fallacy: Jarvis and Okami (2019) point out that saying a successful treatment for a disorder justifies a particular explanation is the logical equivalent of saying that because alcohol reduces shyness, shyness is caused by a lack of alcohol
  • We cannot automatically assume that the success of combined treatments means interactionist explanations are correct, as there is a weak cause-and-effect established
• What is another limitation of the interactionist explanation?

  • Neural vulnerability: Verdoux et al. (1998) found that individuals who experienced obstetric complications at birth are at a 4x greater risk of developing schizophrenia compared to the general population
  • For example, prolonged labour can lead to oxygen deprivation in the brain
  • This shows diathesis may not just be genetic but also brain damage caused by environmental factors, showing the approach is limited