Biological explanation for unipolar depression & Evaluation Flashcards
What does the biological explanation suggest about depression?
The biological explanation for depression suggests that there might be a genetic predisposition towards depression.
How does the biological explanation links genes with depression?
It suggests that genes affect the levels of serotonin in the brain. Serotonin is a neurotransmitter which regulates mood. Also, genes can determine levels of hormones and other bio-chemicals that influence behaviour.
What gene does the biological explanation suggests effects depression and how?
It suggests that a gene 5-HTT helps to regulate a neurotransmitter known as serotonin.
What two forms of this gene are there?
There is a short and long form of 5-HTT
What may people inherit?
A person may inherit two copies of the long form, two of the short, or alternately, one of each
Which form effects depression and why?
Research has found that adults who have the short form of the 5-HTT gene are more likely to experience depression versus adults who carried the long form of 5-HT because The short form is not as effective in regulating serotonin.
What evidence supports the biological explanation of uni-polar depression? (scans)
Brain scans have shown people with depression have irregular serotonin levels.
What evidence supports the biological explanation of uni-polar depression? (twins)
(Kendler) found that concordance rates for depression in mono-zygotic twins were 76% whereas the concordance rates for depression in di-zygotic twins were 19%. These findings do point to genes being an important factor in the development of clinical depression as the concordance rate for mono zygotic twins is much higher than for di-zygotic twins.
Evaluate in terms of applications to real life.
A strength is that it provides useful practical applications to control depression, particularly through drug therapy. Drugs have been produced which cause more serotonin to stay in the synaptic gap for a longer period of time which improves mood. Eg, selective serotonin reuptake inhibitors can be used by patients with depression which cause the serotonin to stay in the synaptic gap longer than it would normally improving the mood of the user.
Evaluate in terms of reductionist.
It is argued that this reductionist explanation could be improved by taking into account environmental stressors which contribute to the development of depression. For example the stress-diathesis model explains depression as an interaction between a biological predisposition to the disorder and environmental stress. Both are necessary for the disorder to develop.
What studies refute the biological explanation for uni polar depression? (2005)
Kirsch et al’s (2005) meta-analysis showed placebos are often as effective as SSRIs, questioning serotonin’s role in depression.
