Psychological theories
Cognitive
Acknowledges the role of biological factors in causing the initial sensory experiences of S, but further features appear as the individual attempts to understand these experiences.
When they first experience voices and other worrying sensory experiences, they to other to confirm the validity of it. These people fail to confirm the reality, so the schizophrenic comes to believe that others must be hiding the truth. Thus, they reject feedback and develop delusional beliefs that others are manipulating persecuting them.
(+) (Meyer-Lindenberg et al., 2002)– link between excess dopamine in the prefrontal cortex and working memory, which suggests a physical basis for the cognitive deficits associated with S.
(+) (Yellowlees et al., 2000)– produced a machine which produces virtual hallucinations, with the intention to show schizophrenics that their hallucinations are not real. ‘Madness’ is a consequence of disbelieving others. No evidence it will be successful.
Socio-cultural factors
Life events
The occurrence of stressful life events has been associated with a higher risk of schizophrenic episodes. These are discrete stresses, such as death of a close relative, or break-up of a relationship.
(+) (Brown and Birley, 1968)– prior to a schizophrenic episode, patients who had previously experienced schiz. reported twice as many stressful life events compared to a healthy control group. 50% of people experienced a stressful life event in the 3 weeks prior to an episode, while only 12% reported one in the 9 weeks prior to that. A control group reported a low and unchanging level, suggesting life events triggered the relapse.
(-) Correlational link- Could be that the beginnings of the disorder were the cause of major life events.
Family relationships
Freud (1924)- Schizophrenia is the result of 1) regression to the pre-ego stage and 2) attempts to re-establish ego control.
A child living in a very hostile environment with cold, hostile parenting may regress to a stage where they were not aware of the reality of their external environment.
Someone with Schizophrenia behaves like a child in the id (selfish) stage, with delusions of grandeur and a demanding nature. They are trying to regain control and according to Freud, that explains the hallucinations.
Double-bind theory
Children who frequently receive contradictory messages from their parents are more likely to develop S.
If a child receives two conflicting messages about relationships the child’s ability to respond to the parent is incapacitated by such contradictions.
These interactions prevent the development of internally coherent construction of reality and this manifests itself as schizophrenic symptoms.
(+) (Tienari et al., 1994)– Individuals with schizophrenic biological parents were more likely to become ill themselves than those with non-schizophrenic biological parents. However, this only emerged in situations where the adopted family was rated as disturbed, thus the illness only manifests itself under appropriate environmental conditions.
(+) (Berger, 1965)– schizophrenics reported a higher recall of double bind statements by their mothers than non-schizophrenics. However, this may not be reliable, as patients recall may be affected by their S.
Expressed emotion (EE)
Associated with a negative emotional climate. It is a family communication style that involves criticism, hostility and emotional over-involvement.
High levels of EE in a family a patient is returning to means the patient is 4 times more likely to relapse than in low EE families.
This suggests that a negative emotional climate arouses a patient and leads to stress beyond their already impaired coping mechanisms, triggering an episode.
(+) (Hogarty et al., 1991)– therapy can significantly reduce relapse rates. However, it is not clear whether the EE intervention was the key element or whether aspect of family intervention may have helped.
(-) Diathesis-stress model- A diathesis stress relationship is the most plausible explanation, with a biological predisposition for developing S, but this will only develop into a disorder if significant psychological stressors occur which act as a trigger.