explanations of schizophrenia

• what is the genetic explanation for schizophrenia?

  • schizophrenia is inherited, this means that it is passed down through the family
  • schizophrenia has candidate genes - specific genes implicated in schizophrenia
  • schizophrenia is polygenic - multiple genes are implicated in schizophrenia, instead of 1 'schizogene'
  • schizophrenia is aetiologically heterogenous - different variations of schizophrenia have different genetic variations e.g schizo-affective disorder has different genes involved than schizotypical disorder
• give research support for the genetic explanation for schizophrenia

  • gottesman (1991)
  • concordance rate of identical twins is 48%
  • concordance rate of first cousins is 2%
  • concordance rate of parents is 6%
  • this shows that the more genes you share with the sufferer, the more likely you are to get schizophrenia
• give research support for schizophrenia being polygenic

  ripke found that there was 108 different genetic variations for schizophrenia
• give research support for the genetic explanation for schizophrenia


  • tienari et al. (2004)
  • found that adoptive children of biological mothers with schizophrenia were more likely to develop the disorder themselves than adoptive children of mothers without schizophrenia
  • this supports that schizophrenia has a genetic cause, if it was due to only nurture, the adoptees wouldn't have developed schizophrenia
• what is the neural explanation for schizophrenia?

  • neural correlates refers to the structure or functioning of the brain is associated with schizophrenia
  • ventricles are fluid filled spaces in the brain (enlarged ventricles are associated with schizophrenia)
  • torrey (2000) research support - found that the ventricles of a person with schizophrenia are on average about 15% bigger than normal
  • the dopamine hypothesis (made up of the old hypothesis, hyperdopaminergia and the new hypothesis, hypodopaminergia)
• describe hyperdopaminergia

  • higher than usual levels of dopamine in the subcortex (central areas of the brain)
  • higher number of dopamine receptors, causing over activity of dopamine
  • this leads to positive symptoms e.g hallucinations
• describe hypdopaminergia

  • lower than usual levels of dopamine in the cortex (outer parts of the brain)
  • less dopamine is being transmitted across synapses
  • this leads to negative symptoms e.g avolition
• give a weakness for the biological explanation of schizophrenia

  • ignores the role of nurture
  • e.g family dysfunction
  • therefore, it is an incomplete explanation for schizophrenia
  • furthermore, a better explanation would be an interactionist approach, which accounts for all influences on human behaviour
• give a weakness for the biological explanation of schizophrenia

  • biological reductionism
  • reduces the complex phenomena of schizophrenia down to dopamine
  • therefore, it is too simplistic
  • furthermore, an interactionist approach would be a better explanation
• give a weakness for the biological explanation of schizophrenia

  • biological determinism
  • as it states that our genes control us and we are doomed if a relative has schizophrenia
  • therefore, it is very pessimistic
  • furthermore, this does not align with the aims of therapy, which states you can overcome schizophrenia
• give a weakness for the biological explanation of schizophrenia

  • alternative explanation
  • e.g psychological and cognitive explanations for schizophrenia
  • therefore, the biological explanation is not a sole explanation for schizophrenia
• give a strength for the neural explanation of schizophrenia

  • real world application
  • anti-psychotics
  • these drugs are taken as treatment for schizophrenia as they relieve symptoms, they work by decreasing dopamine activity
  • therefore, this improves the quality of life of patients and boosts the economy as they return to work and spend on leisure
• give a weakness for the neural explanation of schizophrenia

  • ignores the role of glutamate
  • studies have found raised levels of this neurotransmitter in several brain regions in people with schizophrenia
  • therefore, this means that there are other neurotransmitters involved in schizophrenia that the dopamine hypothesis does not account for, so it is an incomplete explanation
• give a strength for the neural explanation of schizophrenia

  • research support
  • amphetamine
  • this recreational drug mimics the effects of dopamine on the brain
  • when individuals take this drug, they experience schizophrenia-type symptoms such as hallucinations
  • therefore, this provides strong evidence for the role of dopamine in schizophrenia, increasing the credibility of the explanation
• give a weakness for the neural explanation of schizophrenia

  • cause and effect
  • it may be that abnormal levels of dopamine are a consequence of schizophrenia, as opposed to being a cause
  • therefore, we cannot establish causation or say with confidence that dopamine is a cause
• what is the psychological explanation for schizophrenia?

  • family dysfunction refers to being brought up with a family, that has difficulties in communication and high levels of interpersonal conflict
  • having a schizophrenogenic mother
  • double-bind theory
  • expressed emotion
• what are the characteristics of a schizophrenogenic mother?

  • cold, uncaring and rejecting
  • this creates an atmosphere of distrust, this leads to paranoid thoughts which become delusions
• what is the double-bind theory?

  • suggested that children who frequently receive contradictory messages from their parents are more likely to develop schizophrenia
  • because this prevents them from developing an internally coherent construction of reality
• what is meant by 'expressed emotion'?

  • a negative emotional climate with a high degree of 'expressed emotions'
  • a family communication style that has 3 main characteristics

  1. criticism
  2. hostility
  3. emotional over involvement

  • the negative emotional climate in these families arouses the patient and lead to stress beyond their already impaired coping mechanisms, triggering a schizophrenic episode
• give a strength for the psychological explanation of schizophrenia

  • research support for family dysfunction
  • read et. al (2005) found a link between family history of abuse and schizophrenia
  • therefore, this is a strength because it increases the credibility of the psychological explanation of schizophrenia
• give a weakness for the psychological explanation of schizophrenia

  • socially sensitive
  • the psychological explanation for schizophrenia blames the parents, specifically the mother, for the patient's schizophrenia
  • this is an issue because it is parent-blaming
  • parents already have the burden of the ill child, blaming them, makes the burden worse
  • therefore, this is a weakness because this makes this explanation unethical
• give a weakness for the psychological explanation of schizophrenia

  • there is a limited scope for change
  • as it is the family that is causing schizophrenia, there is not much psychologists can do about this
  • you cannot change a schizophrenic patient's family
  • therefore, this a weakness because it limits the usefulness of the family dysfunction explanation, as there is nothing we can really do change it
• give a strength for the psychological explanation of schizophrenia

  • real world application
  • understanding how the family can contribute to schizophrenia, has led to the development of family therapy
  • in family therapy, family members are educated on schizophrenia and try to see the situation from the patient's point of view, with the aim of reducing high levels of expressed emotion and creating a more supportive family climate
  • this will improve the quality of life of patient
  • therefore, this is a strength because it shows the value of the family dysfunction explanation in society
• give a weakness for the psychological explanation of schizophrenia

  • there is the issue of cause and effect
  • we cannot be sure if it is the family dysfunction causing the schizophrenia or whether having a schizophrenic family member causes family dysfunction by creating stress for the other family members
  • therefore, this is a weakness because we cannot claim to have found a cause of schizophrenia, when we may have just found a consequence of it
• give a weakness for psychological explanation of schizophrenia

  • alternative explanation
  • the biological explanation of schizophrenia, states that schizophrenia is due to abnormal levels of dopamine
  • there is evidence for this biological explanation, such as the success of anti-psychotics in treating schizophrenia, which increases the amount of dopamine in the brain
  • therefore, this is a weakness because it decreases the validity of the psychological explanation as a sole explanation of schizophrenia
• what is the cognitive explanation for schizophrenia

  • focuses on the role of dysfunctional thought processes, causing schizophrenia symptoms
  • cognitive deficits and cognitive bias
  • 2 types of faulty information processing (meta representation and central control)
• what are cognitive deficits?

  faulty thought processes cause schizophrenia
• what are cognitive inclinations?

  inclinations to certain thoughts
• what is metarepresentation?

  • refers to the ability to reflect on and have insight into, our own intentions and the actions of others
  • dysfunction in this area - could mean that the individual is unable to recognise that their own thoughts are actually theirs, this can lead to hallucinations and delusions
• what is central control?

  • refers to the ability to suppress automatic responses or triggers in response to stimuli
  • dysfunction in this area - could mean that the individual cannot suppress automatic thoughts that get triggered by other thoughts, this can lead to disorganised speech e.g word salad and disordered thinking
• give a weakness for the cognitive explanation of schizophrenia

  • alternative explanations
  • biological explanation (dopamine hypothesis)
  • psychological explanation (family dysfunction)
  • therefore, this is a weakness because the cognitive explanation is not the sole explanation of schizophrenia
• give a strength for the cognitive explanation of schizophrenia

  • research support for cognitive deficits
  • sterling et. al (2006) compared 30 patients with a diagnosis of schizophrenia with a control group of 30 people without a diagnosis of schizophrenia who completed the stroop test
  • findings - the schizophrenic patients took twice as long to name the ink colours in comparison to the control group
  • this suggests that schizophrenics have cognitive deficits
  • therefore, this is a strength because this research support increases the credibility of cognitive explanation of schizophrenia
• give a weakness for the cognitive explanation of schizophrenia

  • machine reductionism
  • because it reduces the complex phenomena of schizophrenia down to faulty information processes
  • therefore, this is a weakness because this is a way too simplistic explanation for a complex mental illness
  • furthermore, a better explanation would be an interactionist explanation that accounts for the influence for all biological, psychological and cognitive explanations of schizophrenia and how they interact
• give a weakness for the cognitive explanation of schizophrenia

  • issue of cause and effect
  • abnormal cognitions may be one of the consequences of schizophrenia, rather than actually causing the development of schizophrenia
  • therefore, this is a weakness because it means dysfunctional thought processes are not an explanation of schizophrenia, but instead are a symptom
• give a strength for the cognitive explanation of schizophrenia

  • real world application
  • our understanding of the cognitive explanations have led to the development of CBT to treat schizophrenia
  • in CBT for schizophrenia, the therapist helps the patient identify and challenge delusional thoughts and substitute them with non-delusional thoughts
  • treatment improves the patient's quality of life and also boosts the economy as these individuals can return to work
  • therefore, this is a strength because this shows the value of the cognitive explanation of schizophrenia in society