Biological Explanation of Unipolar Depression

virtuoso biologic exposition for unipolar depression is the monoamine hypothesis. The monoamines be a group of neurotransmitters which include serotonin, norepinephrine and dopamine. You will recognise the latter, dopamine, from the biological offering of an explanation for schizophrenia. The monoamines are believed to have mood. One of the functions of serotonin is to regulate the other neurotransmitters. Without the regulation provided by serotonin, terrestrial brain functioning and thinking patterns occur.Low levels of serotonin produces hapless levels of norepinephrine (a neurotransmitter ask for alertness, energy, anxiety and attention to life). Evidence suggests that modest levels of noradrenaline own depression, and spirited levels originator mania, which suggests it is involved both in unipolar and bipolar depression. dopamine is also related to feelings of alertness, motivation and attention, and so it is suggested low levels of dopamine alike are linked to dep ression.Essentially the monoamine hypothesis suggests that low levels of dopamine and low levels of noradrenaline solving in depressive moods, and low levels of serotonin mean low levels of noradrenaline. It excuse-baseation in that locationfore be low levels of dopamine or noradrenaline that result in depression, or a mixture of both. The hypothesis is used to employment with drug treatment, so that the correct drugs (antidepressants) can be prescribed found on the particular monoamine in question. In other words, when a clinician is presented with a patient, they will choose the correct drug that alleviates the presented symptoms of depression.Most antidepressants work by change magnitude levels of serotonin. It cannot be concluded that the explanation for depression is strictly biological. The diathesis-stress model explains how nigh mental disorders can have a biological underlying cause solely require an environmental trigger to become active. Evaluation One strength o f the biological explanation of depression is that there is further semiempirical fend provided by Ogilvie et al. (1996). They showed that cells use a gene called SERT to make serotonin transporter protein which plays an important role in the transmission of information mingled with neurons.In most population, part of this gene called the second intron contains 10-12 repeating sections of DNA. However, slew with depression, only have 9 repeating sections of DNA. This suggests that there is wider academic support for the idea that serotonin is strongly associated with depression. There is much sound show to support the theory, particularly in treatment if the hypothesis suggests the symptoms are repayable to monoamine deficiencies and drugs which replace those monoamines alleviate the symptoms, there is evidence for the hypothesis Kraft et al. 2005) analyze 96 depressed patients treated over 6 weeks with SNRI ( join ons levels of noradrenaline) had a step-down in depressive symptoms compared to those treated with a placebo. Leonard (2000) drugs that lower noradrenaline levels have been found to bring about depressive states. Therefore increasing noradrenaline should decrease depressive symptoms . However, The watch of noradrenaline is recognised by the effects of antidepressant drugs which aim to increase levels of noradrenaline.However, these drugs may also affect other neurotransmitters, so it is difficult to find a clear connection and can be interlined with the critiscism that it is difficult to seduce cause and effect. It the chemical imbalance in the brains of depressed people the cause of the depression or the effect of depression? This issue is further complex by the fact that the answer may be opposite for different types of depression. In endogenous depression perhaps the chemical imbalance comes first, but the other way round in reactive depression.Supporting evidence for the biochemical explanation of depression is that it has practical applications From research into the effectiveness of treatments such as ECT and drugs. ECT supports the biochemical explanation because one shock of cx volts is passed through the brain of depressives for up to 4 seconds. This results in convulsions of up to 2 mins. 6-9 treatments are given of 2-4 weeks. For 60-70% of people with depression, ECT works quickly and effectively. As drugs and ECT alter the balance of chemicals in the brain, it suggests clinicians can improve the choice of peoples lives.One weakness of the biological explanation of depression is that there are exclusive differences. Not everyone who suffers from depression is helped by serotonin-based drugs, which suggests that there are other causes of the disorder. It is also not clear why some people become depressed when their serotonin or norepinephrine level is low, whereas others with the low neurotransmitter level remain depression-free. This suggests that the results gained from such research cannot be genera lised to the square population. Another weakness of the research is that it is biologically deterministics.The cogitate 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 extremity to do anything about it. This suggests that the biological explanation does not account for free will. A final weakness of the biological explanation of depression is that it is reductionist. The reason for this is because it explains depression in terms of genes (SERT) and neurotransmitters (serotonin) and ignores psychological factors such as learning.This suggests that the biological explanation is oversimplistic when explaining depression. Alternative explanations for depression is cognitive explanations which is accounted by Beck (1974) who , cognitive theories take that peoples attributions for events, their perceptions of control and self-e fficacy, and their beliefs about themselves and the world influence their behaviors and emotions when reacting to a situation. In general, an individual with various maladaptive beliefs and attitudes becomes more vulnerable to depression because of his or her generalized negative belief pattern.