Biological Models of Abnormality
Biological and Psychological Models of Abnormality
Introduction
The many different models used to explain the nature and treatment of mental illness compound the problems of defining and classifying abnormal behaviour. Five major schools of thought are summarised below.
The biological (medical) model
The medical of abnormality model has dominated the psychiatric profession since the last century . The underlying assumption of this model is that mental illnesses resemble physical illnesses and can therefore be diagnosed and treated in a similar way. Just as physical illnesses are caused by disease producing germs, genetic factors, biochemical imbalances or changes to the nervous system, it is assumed that this is also true of mental illnesses. Because it assumes that mental disorders arise from such physical causes, the medical model is therefore a biological model.
Example
A patient presenting with symptoms of depression (e.g., extreme tiredness, difficulty in sleeping, lack of interest in life, possible suicidal tendencies) would be diagnosed as having a problem resulting from an imbalance of brain chemicals. This could be corrected by prescribing drugs to restore the balance, or in severe cases ECT (electro convulsive therapy).
Evaluation of the biological model
Assuming that psychological disorders are the result of biological factors is not without its problems. For example, the classification of physical illnesses involves observation and measurement of objective symptoms such as broken bones, fever, blood pressure etc., whereas with mental illnesses, the symptoms are much more subjective — e.g., feelings of despair, lack of energy or hearing voices. These cannot be easily measured, so the clinician must make a judgement based largely on experience.
Also, the difference between physical and mental illness is that diagnosis of physical illness can normally relate to the causes of the problem (known as aetiology). For example,
Introduction
The many different models used to explain the nature and treatment of mental illness compound the problems of defining and classifying abnormal behaviour. Five major schools of thought are summarised below.
The biological (medical) model
The medical of abnormality model has dominated the psychiatric profession since the last century . The underlying assumption of this model is that mental illnesses resemble physical illnesses and can therefore be diagnosed and treated in a similar way. Just as physical illnesses are caused by disease producing germs, genetic factors, biochemical imbalances or changes to the nervous system, it is assumed that this is also true of mental illnesses. Because it assumes that mental disorders arise from such physical causes, the medical model is therefore a biological model.
Example
A patient presenting with symptoms of depression (e.g., extreme tiredness, difficulty in sleeping, lack of interest in life, possible suicidal tendencies) would be diagnosed as having a problem resulting from an imbalance of brain chemicals. This could be corrected by prescribing drugs to restore the balance, or in severe cases ECT (electro convulsive therapy).
Evaluation of the biological model
Assuming that psychological disorders are the result of biological factors is not without its problems. For example, the classification of physical illnesses involves observation and measurement of objective symptoms such as broken bones, fever, blood pressure etc., whereas with mental illnesses, the symptoms are much more subjective — e.g., feelings of despair, lack of energy or hearing voices. These cannot be easily measured, so the clinician must make a judgement based largely on experience.
Also, the difference between physical and mental illness is that diagnosis of physical illness can normally relate to the causes of the problem (known as aetiology). For example,