AO1

• What is the diathesis stress model

  -sees SZ as a result of the interaction between biological (the diathesis) and environmental (the stress) influences.
• The first DS model was proposed by Meehl (1962) who suggested...

  -that the diathesis (vulnerability) was entirely genetic and the result of a single "schizogene"

  -He said that if a person did not have the gene, they would not be able to develop schizophrenia, regardless of much stress they were exposed to.
• However if someone did have the gene

  -then chronic stress through childhood and adolescence, maybe as a result of having a ‘schizophrenogenic mother’, would trigger the gene and result in schizophrenia.
• However after criticism for being too simplistic the model has been revised to account for the discovery of..

  -schizophrenia is a polygenetic condition and there is no single ‘schizogene’.

  -It is also accepted that a range of factors can cause the predisposition or diathesis, and these include physical and psychological trauma that effect the developing brain.
• In addition the range of stressors that can trigger schizophrenia has been widened to include

  -cannabis use, as it appears to increase the risk of developing schizophrenia by up to 7 times.
• Research has shown that a high level of urbanisation is associated with

  -increased risk of developing a range of different psychoses including SZ.

  -Vassor et al (2012) conducted a meta-analysis and found that the risk for SZ in the most urban areas was estimated to be 2.37 times higher than in rural areas.