Psychological explanations for schizophrenia

• AO3 - Evidence for family relationships is often retrospective:

  Read et al. (2005) reviewed 46 studies and concluded that 69% of all adult female inpatients with schizophrenia had a history of physical and/or sexual abuse in childhood. But most of this evidence is based on information about childhood experiences gathered after the diagnosis. The symptoms may have distorted the patients' recall of their childhood experiences. This creates a problem with the validity of the evidence.
• AO3- Evidence for family-based explanations is weak:

  Poor childhood experiences may be associated with schizophrenia, but there is little evidence to support the importance of schizophrenogenic mothers, expressed emotion or double-bind. These theories are mainly based on clinical observations of patients (open to interpretation). They have also historically led to blaming of parents already suffering over their child's symptoms. These issues undermine the appropriateness and credibility of the family-based explanation.
• AO3 - Support for different information processing:

  Stirling et al. (2006) compared 30 patients with schizophrenia with 18 non-patients (control group) on cognitive tasks (eg. in the Stroop Test participants had to name the ink colour of colour words). Participants took over twice as long as the control group to suppress the impulse to read the word and to name the ink colour instead. This supports Firth's theory of central control dysfunction.
• AO3 - Biological factors are sometimes overlooked:

  Psychological explanations can be hard to reconcile with biological ones (eg. genetics). If the biological explanations are valid, how do they fit with psychological ones? Perhaps both biological and psychological factors can separately produce the same symptoms - this raises the question of whether both outcomes are really schizophrenia. Alternatively, we can view this in terms of the diathesis-stress model where the diathesis may be biological or psychological.