INTERACTIONIST APPROACH IN EXPLAINING + TREATING SCHIZOPHRENIA

Sz depends on biological factors (genetics, neurochemicals) + psychological factors (stress)

Diathesis model

SUPPORTING STUDY - TIENARI (2004)

METHOD USED TO ASSESS ADOPTIVE FAMILY FUNCTIONING = ONLY ASSESSED AT ONE POINT IN TIME

ORIGINAL MODEL = OVER-SIMPLIFIED

  • Diathesis refers to vulnerability
  • Stress - refers to a negative psychological experience
  • Interactionist approach states that both stress + genes are needed in order to develop the condition
  • We must be genetically vulnerable but the onset of the condition is triggered by stress

' Schizogene'

  • Without this gene, no amount of stress would lead to Sz, however if you carried the gene, some stress in childhood (e.g. a schizophrenogenic mother) could trigger the condition
  • Original diathesis model states there is a 'schizogene'
  • Modern understanding indicates there is no one single 'schizogene' + many genes increase genetic vulnerability
  • It is now thought that psychological trauma in childhood e.g. sexual abuse, can also affect brain development + may therefore be a diathesis
  • This again indicates that both biology + environment may play a role in the condition

Stress can occur in a number of forms

  • E.g. childhood trauma/living in an urbanised environment
  • Severe trauma before the age of 16 makes you 3 times as likely to develop Sz later in life + the level of trauma is closely linked to severity of symptoms
  • Modern view of stress = not just psychological - cannabis use increases the risk of Sz 7 times according to the dose as cannabis interferes with the dopamine system
  • Most individuals who smoke cannabis don't develop te disorder but it is a risk factor + demonstrates once again that the onset of the disorder most likely requires stress (e.g. cannabis) but also genetic vulnerability
  • Investigated 20,000 Finnish women admitted to psychiatric hospitals diagnosed with Sz + had their offspring adopted away (high risk group), these were compared with adoptees without this genetic risk (low risk)
  • Results = out of the 303 adoptees, 14 developed Schizophrenia + 11 were from the high risk group and being reared in a 'healthy' adoptive family had a protective effect on high risk group
  • This shows that genetic vulnerability + family related stress are important in the development of Sz
  • it is now understood that multiple genes increase vulnerability with each having a small effect + stress can come in many forms, not just parenting
  • Houston states that vulnerability can now be a result of childhood sexual abuse + cannabis is the trigger
  • It is clear that it is not just the diathesis being biological + stress being psychological
  • However, fortunately newer models have addressed this issue
  • This fails to reflect developmental changes in family functioning over time
  • What is also not clear is how much stress is caused by the family + how much stress is caused by the adoptee themselves
  • This questions the validity of the evidence that supports the interactionist approach for Sz

Genetic vulnerability

  • Shown in twin studies
  • Joseph pooled data for all Sz twin studies
    - Found that concordance rates = 40.4% for monozygotic twins + only 7.4% for dizygotic twins
  • However, for 60% of identical twins in which one twin is diagnosed, the other never meets the diagnostic criteria for Sz
  • This indicates that the environment must pay a role in the development of Sz alongside genetic factors

Treatment

  • Interactionist because it combines biological + psychological treatments e.g. CBT + antipsychotics
  • Britain = interactionist approach
  • USA = conflict over interactionist approach with antipsychotics being the preferred choice
  • However, it is unusual to treat Sz only using psychological therapies + interactionist approach to treatment is often adopted successfully

SUPPORTING STUDY - TARRIER ET AL (2004)

  • Patients in the two combination groups shower lower symptom levels than those in the control group (medication only) - but no difference in hosptial readmission
  • This shows that there is a clear practical advantage to adopting an interactionist approach in the form of superior treatment outcomes
  • Randomly allocated 315 patients to a medication + CBT group, a medication + supportive counselling group, or a control group