Biological Explanation of Schizophrenia

Outline and evaluate two or more biological explanations of Schizophrenia

Schizophrenia is a serious mental illness, which causes great distress to its sufferers and family. Many attempts have been made to find its cause so that successful treatment and preventative measures can be applied.

The Genetic Theory of Schizophrenia

A01 Theory

The basic premise of the genetic theory of Schizophrenia is that it is an inherited disorder that runs in families.

A01 Research

There are two ways to test this theory. The first is to identify the gene or genes responsible for causing the disorder and the second is to analyse the frequency Schizophrenia occurs in families.

Zimbardo, 1987 and Gottesman, 1991 have Meta analysed rates of Schizophrenia in first, second and third degree relatives. Their data was collected from European countries between 1920 and 1987. It has shown the following concordance rates: There is a one percent chance that any person in the population could develop schizophrenia, Monozygotic (identical, MZ) twins have a forty-eight per-cent concordance rate for developing the disorder compared to a seventeen percent concordance in Dizygotic (non-identical, DZ) twins. Proponents of the genetic model believe that the significant increase in the MZ concordance rate is because MZ twins have identical genes proving the disorder must be passed down genetically. Other interesting concordance rates are siblings, six percent, Children of two Schizophrenic parents’, forty-six per-cent and spouses of Schizophrenics, two percent.

A02 Research

Overall there are many problems with using family studies. Firstly, they are often retrospective and therefore unreliable; more importantly though, cause and effect is difficult to establish with this method as similarities in concordance may be due to the environment. For example, it is feasible that the children of Schizophrenics develop the disorder more often because they are exposed to the same environmental...