Discuss one or more biological and psychological explanation of schizophrenia (24)

There appears to be a tendency for schizophrenia to run in families. This suggests that genes and biological factors play a role in the explanation of schizophrenia.. The closer the genetic relationship the more likely the people are to share the disorder. Evidence from family studies by Gottesman showed that when both parent are schizophrenic then there is a 46% chance of the child getting it, however, if only one parent had it, it dropped to 16% and dropped to a further 1% when the sibling of the child had schizophrenia. This suggests that a genetic factor is involved. Gottesman also looked at schizophrenics whose father had an identical twin. He found that there was a 17% of being schizophrenic when the father was but he also found that there was also 17% chance of developing the disease when the father’s twin had schizophrenia but the father didn’t.

MZ twins share 100% of their genes; DZ twins share 50% of their genes. If genes are a factor we would expect more identical twins to share the disorder than non-identical. Rosenthal took a case study which had a set of female quadruplets. They all developed schizophrenia although the onset and symptoms were very different. This could have been a result of having a troubled upbringing. This suggests a strong heritable component.

However, most first degree relatives and twins share the same or similar environments so it is difficult to separate genetic and environmental influences. Adoption studies compare people who have been raised in a different environment from their biological relatives. If they have similarities with their biological relatives this should be due to genes. Evidence from adoption studies, such as, Tenari’s study that had a longitudinal study of 155 schizophrenic mothers who gave up their children for adoption. These were compared with 155 adopted children who did not had a schizophrenic mother. Once these children reached adulthood there was a 10.3% chance of developing schizophrenia when the mothers also carried the disease whereas the children who had healthy mothers only had a 1.1% chance of getting schizophrenia

This suggests genes rather than the environment have caused the disorder in these cases.However, adopted twins may still have shared similar environments. Even when the adopted environments are similar there is still the shared experience in the womb and at birth so pre-natal viruses or birth trauma may have had an effect.

Overall the evidence suggests that genes play a part but nature cannot completely explain schizophrenia as there is not a 100% concordance rate. Nurture needs to be considered and the evidence suggests environmental factors must play a part. Without knowing the specific genes involved we can’t explain how these contribute to the development of schizophrenia, however the current advances in research into the mapping of genes may bring more insight to the process.

One of the key psychological explanations of Schizophrenia is the double bind theory, this was developed by Bateson. He proposed that children who frequently receive contradictory messages from their parents are more likely to develop schizophrenia. For example if a mother tells her daughter that she loves her, but at the same time turns away in disgust, the child receives two conflicting messages about their relationship on different communicative levels, one of affection on the verbal level, and one of animosity on the non-verbal level. Therefore, the child becomes confused about how to respond to this situation as the two messages invalidate each other and so the child then develops one of the key symptoms of schizophrenics, that is, withdrawal. This is because it is used as a coping mechanism as it is seen as better to just dissolve away in this social situation instead of make sense of it. This theory also fits in with another major part of schizophrenia this is the inability to construct reality. This is because as the two statements give contradictory messages they cannot interpret this properly. A non-schizophrenic might just think they are turning away because the mother is just getting on with something else but the schizophrenic cannot establish this logic. This theory has some evidence to support it for instance Berger used a retrospective method. He gave out a questionnaire containing 30 double bind statements and asked the participants to rate them on a 4 point scale in terms of how frequently they recalled their mothers using these type of statements. Berger found that the schizophrenics consistently reported a higher incidence of these statements than one of the comparison groups (college students). However he found that the schizophrenics’ scores were not significantly higher than the other comparison groups who also had psychiatric and medical conditions. Therefore, this research provides some evidence for the double bind theory. However with any retroactive study interpretability of findings is limited by the fact that recall may be unequally biased in the schizophrenic group. This is because of their disorganised thought processes. On the otherhand, there is some research that does not support Bateson’s double bind theory for example Liem measured patterns of parental communication in families with a schizophrenic child and found no difference when compared to normal families. Therefore, this statement disproves double bind theory and seems to suggest it is useless.

It was obvious that families may be involved in the progress of the condition, but they are unlikely to have been the cause of it. However, the environment the schizophrenia sufferer returns to after treatment influences the likelihood of successful recovery. Homes where face-to-face interaction is characterised by intense emotional concern or criticism are less conducive to recovery than homes with more emotionally stable interactions. Relapse rates are highest where contact is most fraught.

Brown (1972) showed that patients who returned from hospital to homes where there was a high level of emotionality (High levels of Emotion were Expressed — HEE) were more likely to have a relapse, and would have it sooner than those with LEE (Low levels of Emotion Expressed) families. The kinds of emotions that were expressed were high levels of concern for the sufferers, leading to doing everything for them, being highly critical of their attempts to help themselves, and being very ‘strung out’ generally. These families were characterised by people (mothers usually) rushing around and driving themselves to exhaustion, looking after each other, fussing constantly and being overly possessive. Vaughn and Leff (1976) found 51 per cent of schizophrenic relapses in HEE families, compared to 13 per cent in LEE homes. The more contact the sufferer had with HEE relatives, the higher the relapse rate.
The evidence for the effect of other family members and their emotional responses on recovery from schizophrenia is now well established (and the care package for schizophrenia recovery usually includes some education and support for other family members).

Evidence for the importance of expressed emotion has been found in studies across different cultures so there can be little doubt of its importance in explaining relapse. Unfortunately for the EE explanation, there are also high relapse rates amongst those recovering from schizophrenia who are not in contact with any former family members, so the expressed emotion hypothesis may not be entirely true.