biological explanations of abnormality

Biological Explanations of Abnormality

Mental Disorders/Abnormality = are physical diseases/illnesses

The basic assumptions are:

Brain Damage: abnormal behaviour can occur if the structure of the brain is damaged e.g. people with schizophrenia tend to have larger ventricles in their brain than the normal population and Alzheimer's disease caused by loss of cells in the nervous system.

Infection: bacteria & viruses can cause physical illness but it seems infection can also give rise to mental illness. 

Brown et al (2004) = flu has been linked to schizophrenia as findings suggest that 14% of schizophrenia cases may be linked to exposure to the flu virus in the womb during the first trimester.

Genetics: some people may be genetically at risk of developing mental disorders. Degree relatives of schizophrenia sufferers has approx 10% chance of developing it, this is far in excess to the 1% risk to the normal population.

Human Genome Project = evidence for any genetic disfunctions in DNA

Biochemistry: neurotransmitters are thought to be imbalanced in the nervous system of people suffering from psychological disorders.

excess amounts of dopamine = associated with schizophrenia.                        low levels of serotonin = associated with depression

Three criticisms of the biological explanation of abnormality are:

No Blame: a diagnosis of a mental illness implies that the person is not responsible for their abnormal behaviour therefore it is not their fault and they are not to blame.

Relinquishing Responsibility: people pass on the problem to professionals so they do not feel responsible for their own recovery.

Reductionist: it breaks he biological explanation of abnormality down to the most fundamental level. It is simplistic as many factors can effect and cause pyschological disorders.

One Support for the biological approah to abnormality:

McGuffin at al (1996): conducted research into the risk of schizophrenia in twins and found 46% concordance in MZ twins compared to 20% in DZ twins for depression in a total of 109 twin pairs. This suggests a genetic component in depression.