Biological Explanation Of Abnormality

Biological Explanation Of Abnormality

1. The biological model views mental illness much as it views physical illness and hence refer to psychological problems as ‘illness.’

2. 1. Assumptions

   • Psychological illnesses have a physical cause (genetic, chemical, anatomical etc.)
     • Treatment of psychological illness will require a physical intervention (surgery or drug treatment for example).

3. 2. Explanations

   • Genetic
     • Bilogical illness is inherited from parents. This could be shown if there is a tendency for an illness to run in the family or if a particular gene can be identified as being responsible for the disorder.
       • Usual methods of study include family, twin or adoption studies that look for links between individuals with a similar genetic make up
         • For example if one twin has schizophrenia there is on average about a 42% chance that their identical brother or sister will also develop the disorder. This obviously suggests that schizophrenia is not 100% genetic, but it also suggests that there is a genetic element to it.
   • Biochemistry
     • The brain relies on various chemicals to help it communicate, these are called neurotransmitters. Examples include adrenalin, serotonin and dopamine. Perhaps an imbalance in these chemicals can lead to psychological disorders.
       • We know that LSD can cause similar symptoms to being schizophrenic and we know that LSD is chemically similar to the brain chemical dopamine. There is a clear link between brain chemistry and genes.
         • It appears that the schizophrenic brain is overly sensitive to this neurotransmitter so as a result messages get passed on that would be blocked out in a ‘normal’ brain. Drugs such as chlorpromazine, used to treat some of the symptoms of schizophrenia make the brain less sensitive to dopamine.
   • Neuroanatomy
     • Considers the possibility that abnormal behaviour may be caused by a problem with the structure of the brain
       • We know that brain damage can cause catastrophic alterations to performance and behaviour, for example Clive Wearing
         • There is less evidence to support this aspect of the theory. Possible exceptions are a link between enlarged ventricles (fluid filled chambers in the brain) and some of the symptoms of schizophrenia, and a possible link between the hypothalamus and eating disorders
   • Infection
     • Infections can clearly cause physical illness such as colds, flu, meningitis etc
       • Some evidence has suggested that influenza during the middle section of pregnancy, can lead to an increased incidence of schizophrenia when the child reaches maturity.

4. Evaluation of the biological model

   • The model has lead to a number of widely used and effective treatments for various disorders.
   • Drugs have the added bonus of being quick and easy to take compared to psychological treatments that can take months and be very costly.
   • There is the problem of cause and effect.
   • No psychological disorder has a 100% concordance rate when MZ twins are compared. There are many cases of one twin having a psychological disorder and their identical twin showing no symptoms.
   • There is the danger that if we concentrate on physical definitions and physical treatments that we ignore the root causes of psychological illness