The biological approach studies the relationship between behaviour and the body's physiological systems. The biological (medical) model assumes that all mental disorders are related to a change in the body. An illness or change could be caused by one of four factors: genes, biochemistry, neuroanatomy and viral infection.
Abnormalities in the brain are sometimes caused by genetic inheritance-that passing from parent to child. One way of investigating this is looking at identical twins. Pairs of identical twins can compared to see , when one twin has a disorder, the other has it as well. This gives us a concordance rate-to see how far the individuals are similar to each other in terms of traits. Low concordance rates for mental disorders could be things like a phobia. A high concordance rate for others could be schizophrenia. Many of the genes responsible for particular disorders may carry a particular trait that was useful to our ancestors but not useful for us any longer.
Some Genes can lead to abnormal biochemistry and/or abnormal neuroanatomy:
Genes tell the body how to work. For example, they can determine the levels of hormones and neurotransmitters in the brain (biochemistry). High levels of Serotonin…