PSY 630 CRITICAL REVIEW

Running head: DEPRESSION MEDICATIONS 1

DEPRESSION MEDICATIONS 3

Depression Medications

Lana Eliot

Psychology 630

Professor Brown

September 03, 2018

Depression Medications

Depression is without a doubt one of the most prevalent disorders affecting people all over the world. This makes depression medication the most sort after drug all over the world. It is important to develop an understanding as to how this medication induces action at the neurotransmitter system involved in the disease process. The key symptoms of depression are tackled using antidepressants. These antidepressants work by impinging on chemicals in the brain known as neurotransmitters such as serotonin, norepinephrine, and dopamine (Harmer, Duman, & Cowen, 2017). The key classes of drugs used to treat this disorder include selective serotonin reuptake inhibitors (SSRIs), serotine and norepinephrine reuptake inhibitors (SNRIs), norepinephrine-dopamine reuptake inhibitors (NDRIs), tricyclic antidepressants and monoamine oxidase inhibitors (MAOIs). After consideration of the key classes of drugs used to treat depression, this analysis will not only explain their action at the neurotransmitter system involved in the disease process but also provide an analysis of the agonist-antagonist activity of the drugs and the receptor types and subtypes involved in depression.

As has been mentioned above, these drugs work by initiating action at the neurotransmitter system that is involved in depression. Being that selective serotonin reuptake inhibitors are the most common antidepressants used, this will begin by explaining how it works. Serotonin is neurotransmitters in the brain that are responsible for carrying signals between cells in the brain. This particular antidepressant works by increasing the levels of this neurotransmitter in the brain. This it does by inhibiting a process called reuptake in which serotonin neurotransmitters in the brain are reabsorbed to allow an optimum level (Hiemke & Härtter, 2000). Owing to their function

as signal carriers between brain cells, the availability of more serotonin neurotransmitters means that there is more signal communication between brain cells. These antidepressants are called “selective” because of their tendency to affect only serotonin as opposed to other neurotransmitters in the brain.

On the other hand, serotine and norepinephrine reuptake inhibitors work much in the same way as SSRIs. However, they are not selective and are able to inhibit the reuptake of both neurotransmitters serotonin and norepinephrine. Norepinephrine is a neurotransmitter that mobilizes the brain and body and is released in high amounts when someone is stressed or awake. Therefore, it is the main neurotransmitter that coordinates concentration, alertness, and motivation. Moreover, this neurotransmitter by extension has an impact on regulating feelings of pleasure and mood. Like the antidepressants highlighted above, norepinephrine-dopamine reuptake inhibitors are drugs that work through a process called reuptake inhibition. These drugs inhibit the reuptake of neurotransmitters norepinephrine and dopamine. Dopamine is one of the most important neurotransmitters in the brain as a result of the wide variety of functions it has including coordination of executive functions, reward, motor control, reinforcement and motivation among others. In the same manner that mood is regulated through reuptake inhibition, cyclic antidepressants work by inhibiting the absorption of neurotransmitters serotonin and norepinephrine. Each of the antidepressants explained above objectify the inhibition of the reuptake process for essential neurotransmitters whose availability is critical to functions such as mood regulation and motor control among many others. On the contrary, monoamine oxidase inhibitors work by inhibiting the action of monoamine oxidase whose function is to remove

neurotransmitters from the brain such as norepinephrine, serotonin, and dopamine (Mathew, et al., 2016). The outcome is increased levels of all the three neurotransmitters in the brain.

The preference in the prescription of these drugs for depression is often determined by the nature of side effects resulting from the use of the drug. This depends on an agonist-antagonist relationship in which a drug may behave as an agonist in some conditions or antagonist in others. As an agonist, the drug activates the receptor it binds to while fails to activate after binding when the drug acts as an antagonist. The drug SSRI cannot be characterized as either an agonist or antagonist because it does not impinge on the post-synaptic region as would have been the positive outcome of an agonist-antagonist relationship. On the other hand, SNRIs have been reported to exhibit mixed agonist and antagonist actions. To be specific, both SSRI and SNRI have been found to exhibit dopamine receptor antagonism. While NDRIs are no known to exhibit this relationship, MAOIs have the potential to cause serotine syndrome which may be indicative of selective mixed agonist and antagonist actions.

When prescribing depressant medication, the critical consideration is made of the potential side effects of each. As already mentioned above, SSRIs are the most prescribed antidepressants because they are not known to have any side effects. However, there is advice of caution on potential effects such as drowsiness, nausea, and insomnia among many others. Additionally, owing to the structural similarities with SNRIs, their side effects are closely similar. On the other hand, NDRIs are equally commonly used with Bupropion being the most popular type of NDRI. It has much fewer side effects as compared to other antidepressants and is thus used many times as a drug for anxiety. Occupying one of the lowest spots in this list is tricyclic antidepressants

known to have serious side effects which vary from one drug type to the other. Side effects associated with this antidepressant include blurred vision, constipation, drowsiness, dry mouth and urine retention among other. Monoamine oxidase inhibitors are the least preferred antidepressants because they have far serious side effects than all the others explored in this analysis. These drugs have the potential to equally interfere with neurotransmitters in the brain and the digestive system. The large array of potential side effects associated with this drug include dry mouth, headache, drowsiness, insomnia, nausea, diarrhea, and dizziness among many others.

An evaluation of the risk benefits of drug use for depression is dependent on how the various classes of drugs explored in this analysis compare to each other. It is clear from the analysis of actions at the neurotransmitter system that most of these antidepressants work in the same way, by inhibiting reuptake of neurotransmitters (Harmer, Duman, & Cowen, 2017). Most do this successfully and create the effect of improving the potential of the patient to coordinate fundamental actions such as mood regulation, motivation, and motor control. However, the limitations of these drugs are the side effects; it is clear that there are antidepressants that have fewer side effects while others have serious side effects. This means that by consideration of different types of drugs available for depression, it is possible to select one that works well and has fewer side effects. The availability of this degree of choice makes the consideration of depressant medications a potentially positive decision, especially when the patient’s condition is compatible with SSRI and SNRI because they have the least side effects. However, a depressive patient who must use either tricyclic antidepressants or monoamine oxidase inhibitors is in risk owing to the known serious side effects associated with these choices.