the diathesis-stress model of schizophrenia

overview of the diathesis-stress model

• The diathesis-stress model is based on holistic approach to explaining a range of disorders, including depression and schizophrenia

• The diathesis-stress model assumes that schizophrenia does not stem from one main source but is instead a combination and interaction of biological, psychological and social factors

• The original model (Meehl, 1962) suggests that if someone has a genetic vulnerability (diathesis) to schizophrenia, this will be triggered by a stressful event or situation

  • Situational stressors work to bring about the illness or to intensify symptoms of the existing illness

• The more vulnerable a person (i.e. the higher their diathesis), the less stress is need to trigger schizophrenic symptoms

• The diathesis-stress model has undergone some revision and modification since its early inception in the 1960s:

  • Diathesis may come in many forms

    • Biological - specific genes which predispose a person to schizophrenia

    • Psycho-social - early experiences of abuse and bereavement

  • Stress may also come in may forms and may form the basis of the diathesis rather than being a trigger (e.g. living with a parent who has a mental illness)

  • Jones & Fernyhough (2007) suggested that a neural diathesis-stress model of schizophrenia, which proposes that stress heightens cortisol levels and that this triggers the symptoms of schizophrenia

protective factors & the diathesis-stress model

• Protective factors in someone’s life may guard against the potential harm of the various risk factors that could trigger schizophrenia:

  • The risk factor of toxic parenting could be offset by having caring grandparents who offer the love and nurture a child needs

  • Personal traits such as resilience, optimism and stoicism can also help to protect a vulnerable individual

  • Protective factors may highlight why one person with roughly the same diathesis/stress in their life does not develop schizophrenia compared to someone else who does

research which investigates the interactionist approach

• Pruessner et al. (2017)

  • Published a review article focusing on the neural diathesis-stress model in light of a more sophisticated understanding of the role of the hypothalamic-pituitary-adrenal (HPA) system in a wider neurobiological context, including the effect of early stress on brain structure and development

    • The review highlighted the significance of considering both biological and environmental factors in understanding and treating schizophrenia

• Silverton (1988)

  • Found that a sample of participants who had schizophrenic parents were more likely to develop schizophrenia and to engage in criminal behaviour if they had show short attention spans as infants which supports the original diathesis-stress model

    • Some people may have a genetic vulnerability to schizophrenia, which is marked by distinct behaviours in early childhood

• Walker et al. (1989)

  • Found that families in which there are parental mental illness and mistreatment of children were more likely to produce children who showed increasingly  schizophrenic behaviours and symptoms

strengths of the interactionist approach for schizophrenia

• Research such as Tienari (2004) lends strong support to the model, as it highlights the interplay between biological and psycho-social factors in the development of schizophrenia, which means that the model has good validity

• The model could be applied to form intervention strategies such as resilience-building, mentoring programmes, and social skills training, so it has some external validity

weaknesses of the interactionist approach for schizophrenia

• The model has been criticised for not acknowledging the role of other biological factors, such as the role of neurotransmitters (e.g. the dopamine hypothesis) in the development of schizophrenia, which means that it may offer only a partial explanation

• There is some vagueness over exactly how biological, psychological and social factors interact according to the model, which means that it lacks objectivity

links of the interactionist approach for schizophrenia to issues & debates

• The diathesis-stress model supports an interactionist approach, recognising that both nature and nurture contribute to the development of schizophrenia

  • This offers a more balanced and realistic explanation compared to purely genetic or purely environmental theories

• Unlike single-cause explanations, the diathesis-stress model is holistic, accounting for biological, psychological, and social influences on schizophrenia

  • This means it is more useful for designing individualised treatment plans