First 658 words of the document:
Outline clinical characteristics of schizophrenia.
Often confused with a split personality, schizophrenia is a severe psychotic disorder that involves
abnormal thoughts and perceptions. It has been described as a disintegration of the personality. The
person loses insight, loses touch with reality and fails to realise they have a problem. It involves a
range of psychotic symptoms where there is a break from reality. There are two types of
schizophrenia, type one is characterised by positive symptoms (something that is added to the
sufferer's personality) such as bizarre delusions, hearing voices, disorganised thoughts and speech
etc. Type 2 is characterised by negative symptoms (something that takes away from the sufferer's
personality) such as apathy, stereotyped movements, withdrawal, isolation etc.
Discuss one biological and one psychological explanation of schizophrenia.
One explanation is the genetic hypothesis. Genetic studies e.g. Gottesman show that the risk for an
individual developing schizophrenia is proportional to the amount of genes they share; MZ twins
have a 48% risk, children of two affected biological parents have a risk of 46%, DZ twins or children
with one affected parent have a risk of 17%, and for the general population the risk is only 1%. This
suggests that genetics play a significant role in the onset of schizophrenia, however it is not 100%
caused by it. Kety supports this from their study in which they found higher concordance rates for
adoptive children and their biological parents when their environments were matched. There are
limited environmental factors that could cause the child or parents to be more likely to develop
schizophrenia which indicates that genetics play an important role in developing schizophrenia.
However, Loehlin and Nichols suggest that the higher concordance rates with MZ twins could be due
to being treated the same so it may be due to environment rather than genetics. Twin studies as a
whole do show strong genetic evidence for schizophrenia. However they are never 100%
concordant, thus suggest a genetic predisposition rather than a genetic cause for schizophrenia.
Another issue is that twin studies of schizophrenia have small sample sizes; schizophrenia is evident in
1% of the population and twins with schizophrenia are even rarer, so it is hard to generalise to the
rest of the population and difficult to determine whether these studies are reliable or not.
Another explanation is cognitive; this accepts that initially sensory experiences may be biological. It
suggests that schizophrenics cannot distinguish between information that is already stored and new
incoming information. As a result, schizophrenics are subjected to sensory overload and do not know
which aspects of a situation to attend to and which to ignore. Meyer-Lindenberg et al. found a link
between working memory and reduced activity in the pre-frontal cortex in people with
schizophrenia. This suggests that inferior working memory has an impact on schizophrenia and thus
supports the cognitive explanation. Schielke et al. studied a patient who developed continuous
auditory hallucinations as a consequence of an abscess in dorsal pons. This suggests wider academic
credibility for the link between cognitive and biological factors causing schizophrenia. However it is a
case study thus has issues with high individual differences and not being able to generalise to the
wider population so it isn't reliable. In terms of nature vs. Nurture, psychological explanations back
nurture as they suggest schizophrenia is caused by environmental factors such as cognitive
deficiencies. However, it is environmentally deterministic as it ignores factors such as free will and
biological factors. Another issue is that we don't know whether schizophrenia is caused by cognitive
problems, or rather that they are a result of schizophrenia. Cognitive approaches are also
reductionist as they don't consider factors such as genes, it could be problems caused by low