Discuss The Biological Explanation for Depression and Biological Treatments for Depression The biological explanation or the ‘medical model’ would favour the nature side of the nature nurture debate. This approach or explanation of dysfunctional behaviour / depression asserts that something in our biology or genetic makeup is the cause of the affective disorder depression. / dysfunctional behaviour such as depression. A number of things such as genetics (a predisposition), biochemical imbalance or even malformation of the structure of the brain are seen to contribute in their own ways to a person suffering from depression.
Research has provided evidence to suggest that depression, a mood disorder, may be caused by other family members being diagnosed. Having a first degree relative (parent or sibling) with depression appears to be a risk factor for depression. Family studies such as Wenders select people who already depression. Twin studies also provide evidence of depression running in families. In Wenders study (1986) they looked at the biological relatives of adopted people who had been hospitalised for severe depression. The study found a much higher incidence of severe depression in those relatives than those of a non-depressed control group Wender concluded from this research that there is a significant genetic link between unipolar depression and suicide as there were 15 times more suicides amongst the biological relatives of the participants with mood disorder compared to the adoptive parents.
One strength of the research into the genetic explanation for depression comes from the empirical support it provides; twin studies in monozygotic twins and dizygotic twins provide strong evidence to suggest genetic causation for depression and other disorders such as schizophrenia ( Gottesman and Shields). For example Bertelsen found a concordance rate of 80% of bipolar with MZ twins, but a rate of only 16% for DZ twins. This evidence suggests that there is a wider academic support that genetics play a part in affective disorders such as depression.
One weakness of the genetic explanation is that there is a problem of the nature nurture argument. It is sometimes difficult to separate out the influence of nature/nurture. Whilst the twin studies provide strong evidence for the role of genetic factors and the adoption studies point to the role of nature over nurture this is not conclusive. A further problem with the research is that there is an issue with population validity. The reason is because the samples used in such studies such as Wendlers are so small and there is therefore difficulty in generalising the results to the rest of the population.
Although biochemical explanations have also furthered our understanding of depression being due to neurotransmitters ; low levels of norepinephrine leading to depression and high levels to mania and Serotonin theory suggesting low levels produce depression too, Mann et al found impaired serotonic transmission in people with depression, thus providing us with further evidence to suggest biochemical explanation. One criticism of the biochemical explanation is that it is difficult to establish cause and effect – is it the chemical imbalance in the brains of depressed people the cause of the depression or the effect of depression. This suggests the chicken and egg problems faced with the biochemical explanation.
Furthermore another weakness is the research is biologically deterministic. The reason for this is because it suggests that individuals who have low levels of serotonin are determined to suffer from depression in later life. However people have a choice about their behaviour and whether they want to do anything about it. This suggests the biological explanation does not account for free will. The final weakness of the biological explanation of depression is that is reductionist. The reason for this is because it explains depression in terms of one’s genes and neurotransmitters and ignores psychological factors such as learning. This suggests that the biological explanation is over- simplistic when explaining depression.
In contrast the psychological explanations reject the view that depression is caused by biological factors. Instead it favours the idea that the disorder is caused by traumatic life events such as loss, death of a close relative, even divorce. Theses can lead to a cycle of disturbed and negative thinking which perpetrates the depression. This suggests that perhaps people are born with a genetic tendency towards depression but it also takes certain life events to trigger it off. In conclusion the diathesis stress model which suggests that there is a genetic vulnerability to a disorder (diathesis), but that this is triggered when an individual has been exposed to a stressful life event. Both these factors are necessary for a disorder to develop.