The interactionist approach to schizophrenia

Interactionist approach

Acknowledges that there are biological and social factors impacting SZ

Diathesis stress model

Both a vulnerability and stress trigger are needed to develop SZ

Meehls model (1962)

Diathesis vulnerability was entirely genetic as a result of a ‘schizogene,’ if a person does not have this gene then no amount of stress will lead to SZ BUT those with the ‘schizogene’ means stress during childhood (e.g. schizophregenic mother) could lead to SZ

The modern understanding of diathesis

Ripke (2014) there is not one single gene that makes you develop SZ

Read (2001) diathesis can be other factors like psychological trauma. For example childhood trauma can lead to the hypothalamic-pituitary adrenal system can become overactive, leading to more vulnerability to stress

The modern understanding of stress

Psychological stress can still be due to the parent, but it can also be in cannabis use. Cannabis is a stressor because it increases risk SZ by 7x, but most people do not develop SZ after smoking cannabis so there are other factors

Interactionist treatment

Combining CBT and antipsychotics. Medication and CBT is more common in the UK compared to America

Support for the role of vulnerability and triggers

Tienari (2004) investigated the impact of both genetic vulnerability and a psychological trigger (dysfunctional parenting). Followed 19,000 Finnish children with biological schizophrenic mothers compared to adoptee control group.

High levels of criticism, hostility and low levels of empathy, high genetic risk group associated with the development of schizophrenia.

Oversimplified original model

Multiple genes influence diathesis. Stress also comes in many forms, including but not limited to dysfunctional parenting.

Houston (2008), found childhood sexual abuse emerged as the major influence on underlying vulnerability to schizophrenia and cannabis use as the major trigger.

Real-world application

Combining treatments enhances effectiveness.

Tarrier (2004) randomly allocated 315 participants to

(1) medication + CBT

(2) medication + counselling,

(3) control group (medication only).

Combination groups = lower symptoms than 3. Though there was no difference in hospital re-admission.