Monoamine Theory Essay

Since the discovery of monoamine oxidase inhibitors (MAOIs) and tricyclic antidepressants in the 1950s and its affect on depressives, Schildkraut first proposed the Monoamine Theory. The theory states that depression is caused by an imbalance of monoamine transmitters (neurotransmitters) in certain areas of the brain, such as noradrenaline, serotonin and dopamine (Schildkraut, 1965). This led to the introduction of antidepressant medication in the treatment of depression, known as pharmacotherapy. However, ongoing research suggests that the theory is “inadequate, as it does not provide a complete explanation for the actions of antidepressants, and the pathophysiology of depression itself remains unknown.”(Hirschfeld, 2000) A few of the main reasons for this inadequacy are because it is difficult to measure the level of neurotransmitters in an individual’s brain (P. L. Delgado, 2000) and that evidence is indirect on whether monoamine function is impaired in individuals with depression as the causes of depression appear to be more complex than simply a reduction in levels of monoamine or diminished function in these systems. (P. Delgado & Moreno, 1999)

However, a more direct investigation of the role of monoamines can be used through the neurotransmitter depletion model that can be seen in an experiment with tryptophan depletion and alpha-methylparatyrosine, which is used to lower levels of serotonin and induce catecholamine depletion, respectively, in the brain (Salomon, Miller, Delgado, & Charney, 1993). Results from this experiment show that, depending on the antidepressant used, such depletion rapidly reverses antidepressant responses in the majority of patients and that depletion in unmedicated patients with depression did no...

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...d that in four treatment trials, cognitive therapy for depression is superior to pharmacotherapy in reducing relapse, or the need for further treatment. (Blackburn, Eunson & Bishop, 1986; Simons, Murphy, Levine & Wetzel, 1986; Evans, Hollon, De Rubeis, Piasecki, Grove, Garves & Tuason, 1992; Shea, Elkin, Imber, Sotsky, Watkins, Collins, Pilkonis, Leber, Krupnick, Dolan & Parloff, 1992). Therefore, it can be seen that many qualitative and quantitative reviews now conclude that cognitive therapy effectively treats depression, or is at least comparable, if not, superior to medication treatment, and may have lower rates of relapse in comparison to medication treatments. As a result, the implications of the cognitive theory and the treatment used to process Beck’s theory, cognitive therapy, has been a successful treatment in regarding depression, and many other diseases.