Biological Theory of Depression

The Biological Theory states that the cause of depression is a biological one in which there is a shortage of Noradrenaline and Serotonin in the synaptic clepts of neurons in the brain. The study of imbalances of Serotonin is more common that that of other neurotransmitters. However, studies show that there is not only a decrease in these chemicals, but an imbalance in the regulatory patterns and consequent overactivity of certain transmitters in some areas in the brain. A molecular and cellular theory of depression states that stress causes vulnerability and the therapeutic action of antidepressant treatments occur via intracellular mechanisms that decrease or increase, respectively, the neurotrophic factors necessary for the survival and function of particular neurons.

Proof of the validity of the Biological theory of depression lie in the biological alterations that accompany depression. The corticosteroid overdrive and noradrenergic hyperactivity present in depression may impair the normal functions of the immune system. A correlation between depression and coronary heart disease, rheumatoid arthritis, and stroke has been established by a theory called the macrophage theory of depression. The most obvious proof of the Biological theory of depression is the aleviation that comes from taking antidepressants that try to minimize imbalances and other biological problems that are thought to cause depression.
Sources
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