Discuss two biological explanations of 
Discuss two biological explanations of depression (8+16 marks)
AO1:
One biological explanation for depression is family studies. Family studies have proved that having a first-degree relative with depression appears to be a risk factor of depression. These studies select people who already have the depression (the probands) and examine whether other members of their family have been, or might be diagnosed with depression. Research has found that around 20% of such relatives have depression compared to a figure of around 10% for the population at large.
A second biological explanation of depression is twin studies. McGuffin et al (1996) studied 177 probands with depression and their same sex co-twins. The concordance rate was 46% for identical twins and 20% for fraternal twins, suggesting that depression has a substantial heritable component.
Another way in which to examine genetic factors on depression is by using adoption studies. Wender et al (1986) studied the biological relatives of adopted individuals who had been hospitalised for severe depression. They found a much higher incidence of severe depression in the biological relatives of the depressed group than in the biological relatives of a non-depressed control group.
Genes and diathesis is a further explanation for depression. Genetic factors are thought to act as diathesis in a diathesis-stress relationship. Such a view would see a genetic predisposition for depression interacting with environmental stressors to produce a depressive reaction. We might expect, therefore, such environmental stressors to affect those with the genetic predisposition differently to those without it.
AO2:
The importance of genetic factors in depression is supported by Oruc et al (1998) who found that depression occurs across generations in families, and that first degree relatives of people with depression are three times more likely to develop the disorder than those without first-degree relatives with the disorder.
The
AO1:
One biological explanation for depression is family studies. Family studies have proved that having a first-degree relative with depression appears to be a risk factor of depression. These studies select people who already have the depression (the probands) and examine whether other members of their family have been, or might be diagnosed with depression. Research has found that around 20% of such relatives have depression compared to a figure of around 10% for the population at large.
A second biological explanation of depression is twin studies. McGuffin et al (1996) studied 177 probands with depression and their same sex co-twins. The concordance rate was 46% for identical twins and 20% for fraternal twins, suggesting that depression has a substantial heritable component.
Another way in which to examine genetic factors on depression is by using adoption studies. Wender et al (1986) studied the biological relatives of adopted individuals who had been hospitalised for severe depression. They found a much higher incidence of severe depression in the biological relatives of the depressed group than in the biological relatives of a non-depressed control group.
Genes and diathesis is a further explanation for depression. Genetic factors are thought to act as diathesis in a diathesis-stress relationship. Such a view would see a genetic predisposition for depression interacting with environmental stressors to produce a depressive reaction. We might expect, therefore, such environmental stressors to affect those with the genetic predisposition differently to those without it.
AO2:
The importance of genetic factors in depression is supported by Oruc et al (1998) who found that depression occurs across generations in families, and that first degree relatives of people with depression are three times more likely to develop the disorder than those without first-degree relatives with the disorder.
The