Chemistry of Antidepressants Term Paper

Introduction

Depression

Depression is an unexceptional psychological disorder that is characterized by guilt feelings, low self-esteem, perturbed sleeping episodes, suppressed mood, lack of appetite, interest, or passion as well as the inability to concentrate (3).

Causes

The actual cause of depression has not been known yet by psychological experts. However, research studies have conclusively demonstrated that females are more likely to encounter depression episodes two times as much as males (6). Nevertheless, the following illustrations have been used to explain the likely causes of depression.

Significant Losses

A gross loss in an individual’s life can prompt depression. For instance, losses occasioned by the death of a loved one or acquaintances and family breakdowns due to divorce or separation besides being hopeless and lack of self-identity (1).

Hidden anger

Anger that is not outwardly expressed can be a very powerful cause of depression. Those people who prefer to keep to themselves and not comment or complain at all even if they are pressed up or uncomfortable are more likely to get depressed than those who openly speak out or express their rage (11).

Hormonal imbalance

There are pertinent brain chemicals like serotonin which are often less in amount among individuals who are undergoing depression. Insufficient brain chemicals may also cause depression (4, 9).

Family history

The genetic factor attached to family lines also plays a very important role in the cause of depression (8). Some people develop depression due to genetic vulnerabilities passed on from parent to offspring.

Gender

Research studies have revealed that females are twice as likely as males to become depressed (17).

Stress development

Persistent stress episodes occasioned by such factors like financial hardships and chronic illnesses can easily transform to depression (14).

Perfection

The desire to achieve the best through seeking utmost perfection in one’s undertaking is a known cause of depression (5).

Symptoms

Depressed individuals are often sad right from their physical appearance. This state of sadness doesn’t seem to dissipate but rather lasts for infinitely long period of time. The onset of depression is often evident when the affected person no longer derives passion or interest from most activities and everything appears to be dull (16). Besides, depressed persons tend to withdraw from people and other normal activities. Moreover, restlessness which is beyond the activity level of a person can be a good indicator of depression. This is sometimes accompanied with erratic behavioral patterns like episodes of moaning or crying (7, 13).

Low levels of activity coupled with extreme difficulty of undertaking certain common exercises can be symptoms of depression. Finally, depressed individuals tend to be less motivated and they partially or completely lack initiative to do things on their own. Other general symptoms include numbness, anxiety, low self confidence and a state of helplessness. Certain signs in the body such as fatigue, poor appetite, and bad sleeping habits can be indicators that a person is undergoing depression (8).

In medicine or pharmacology, an antidepressant refers to any drug that can be used to treat, cure, alleviate or act as a remedy to depression. In 1957, Roland Kuhn made the preliminary step towards the discovery of the first antidepressant. This was based on the fact that an organic compound with three rings in its structure was capable of alleviating depression. Antihistamine were prominently used in the treatment of certain shocks related to surgery and was not considered as an antidepressant at all (6). By mid 1950s, reserpine had been proved to be a better option especially in reducing the effects of depression caused by anxiety. This was also one of the drugs which were being developed around this time to control nerves and also act as sedatives (5).

Types of antidepressants

The market today has a variety of antidepressants that are used in the treatment of depression (6). Each of the antidepressants has a unique mode of action although all are meant to reduce the effect of depression. Serotonin which is selective in nature is still new in the market.

Tricyclic antidepressants

This is one of the most notable classes of antidepressants available today. They derive their name from the three ringed structure in them and which also determines their mode of action. Imipramine is one of the antidepressants that belong into this class. Its discovery took place in the 1950s (10). Generally, the tri-cyclic antidepressants have been used in the cure of quite a number of disorders that are associated with bipolar in addition to alleviating depression as well.

Mode of action

The reuptake blocking of crucial hormones from the brain is the main mode of action of most trcyclic antidepressants (2, 9). Usually, there are two main hormones that are blocked during the process of treating depression namely norepinephrine and also serotonin which are regarded to be neurotransmitters. These two brain hormones are critical in the onset and development of depression as a psychological disorder. Nevertheless, trcylic antidepressants are known to cause serious allergies to certain category of patients and who may be required to seek further medical help in the event that they cannot cope with the drug (7).

On the same note, babies who are undergoing breastfeeding may be equally affected by tricyclic antidepressants if they are taken by breastfeeding mothers because the drug can be passed to the mother’s milk. There are several brands of tricyclic antidepressants which are common in the market although all of them perform the same function. Examples include amitriptyline, clomipramine, dimetacrine and desipramine among others

This class of antidepressant are primarily used in the treatment of psychological disorders related to mood, bipolar as well as those disorders attached to impression. All these disorders are closely related to depression (17). Some of the adverse effects of tricyclic antidepressants include but not limited to dry mouth, blurred vision accompanied by dizziness, gain in weight and constipation.

Selective serotonin reuptake inhibitors (SSRIs)

This class of antidepressants is very popular for use in the treatment of depression. Fluoxetine was the first ever type of SSRI used during the late 80s.

Mode of action

The way in which this class of antidepressant affects the treatment of depression is not clearly known (4). Neurotransmitters are brain chemicals that are usually linked to depression. Also included in this group of brain chemicals is the neurotransmitter serotonin. Based on some research studies, it has been established that both behavior and mood are affected by the prevalence of any abnormalities n these brain chemicals. The mode of action of SSRIs is such that it tends to cause blockage of serotonin from being reabsorbed. When this happens, certain symptoms of depression are relieved considerably.

Hence, the reuptake of this substance is blocked by certain cells in the brain. As a result, more serotonin is made available. When the brain has plenty of serotonin, neurotransmission is greatly enhanced (12). This refers to the process through which nerve cells in the brain send impulses thereby improving an individual’s state of mood. Out of this mode of action, only serotonin is affected. Hence, this is the selective mature of SSRIs. Other neurotransmitters are usually not affected (14).

There are several SSRIs which have been approved for use in treating depression. For instance, citalopram, paroxetine and fluoxetine are some of the SSRIs currently in use. Although SSRIs are potentially used to alleviate depression, they have a couple of side effects which cannot be avoided. The mode of action as well as the side effects of SSRIs is similar in one or the other. Nonetheless, there are pharmacological features those are different among individual SSRIs.

Hence, depressed patients are more likely to experience unique differences and also respond differently when they use various types of SSRIs. Some of the adverse effects include nausea, headache, inability to function well sexually, diarrhea and dry mouth. Besides, depressed patients may also become nervous and restless. In some cases, SSRIs may lead to over sweating and gain in weight of an individual (13).

Serotonin and Norepinephrine reuptake Inhibitors (SSNIs)

This class of antidepressants are also used to reduce the symptoms of depression. Depressed individuals who may be sad or irritated can use this class of drug whose inhibition is dual uptake.

Mode of action

The quantity of both serotonin and norepinephrine are significantly increased by serotonin and norepinephrine reuptake inhibitors (SNRIs). It does this by preventing the reuptake of the brain chemicals. As a result, neurotransmission levels are increased. This has a direct effect on mood of the depressed person who tends to lighten up. Besides, this class of antidepressants can also increase the sensitivity of the brain cells (6). The nerve cells are generally supported from glutamate. Examples of drugs under this category include duloxetine and venlafaxine. Some of the adverse effects of SNRIs include vomiting, insomnia, sweating, abnormal dreams, nausea, anxiety and yawning among others.

Monoamine Oxidase Inhibitors (MAOIs)

This category of antidepressants have been used for the longest period of time.

Mode of action

The monoamine enzyme is prevented by this antidepressant from the process of metabolisms of neurotransmitters which are located in the brain. Hence, the mood of the depressed person is boosted due to high levels of serotonin, norepinephrine and dopamine sustained in the brain (12). Examples of drugs in this category include selegiline, phenelzine and isocarboxazid. Some of the notable adverse effects of using this antidepressant include drowsiness, fatigue, diarrhea and decreased pressure of the blood and low volume of urine output.

Side effects of antidepressants

There are a myriad of side effects caused by the use of antidepressants in treating depression. One such common side effect is nausea. Individuals develop nausea roughly seven days after the onset of drug use. However, after the body familiarizes itself with the antidepressant, the nausea eventually disappears. One way of coping is by taking the drug alongside enough food. However, the amount of food taken is recommended to be small although taken on a regular basis (1). In addition, it is recommended for depressed individuals to take plenty of fluids that have no sugar.

Another side effect is weight gain which is occasioned by increased appetite. A lot of fluid retained in an individual’s metabolic system or lack of physical exercise is some of the aggravating factors. It is important for individuals under depression to eat healthy food, do plenty of exercises, take foodstuffs that have low sugar content and also seek help from a nutritional expert (9, 13).

Serious Risks Associated with Antidepressants

Insomnia is common among patients who take SSRIs. Other physical symptoms include severe headaches, diarrhea, rashes as well as pains on the muscles and joints. Besides, patients may become nauseated and experience episodes of stomach upsets. These risks may range from temporary to mild (11).

Some antidepressants can cause bleeding complications. In addition, reduced ability for blood to clot is also a common problem. As a result, both the stomach and uterus may bleed thereby endangering the life of patients. In the event that antidepressants like SSRIs class are combined with others lie NSAIDS, the potential risk to patients may even double and hence any combined use of these drugs should be done with extra care.

Additionally, SSRIs have the ability to reduce sexual desire, passion, performance or even contentment. The effect can be reduced by taking small dosages of the drug. The continual use of antidepressants has also been associated with high risk of suicide due to mood changes. There is a high number of young population who are under medication for antidepressants and it is equally believed that the more they use these antidepressants, the more they develop suicidal thinking an d eventually commit the act (14). It is important to monitor and make follow ups of the patients who are under prescription of these drugs.

Another risk of using antidepressants is binge eating , the main characteristic of bulimia nervosa (2,17). The person eats quite frequently like within a span of two hours. The quantity of food eaten is rather excessive. This is repeated regularly. The individual also has a feeling that he or she is unable to take control of the amount of food taken at any given time. In order to overcome the effects caused by their eating disorders, bulimia nervosa patients may fast or avoid food, induce vomiting or excessively use laxatives.

Conclusion

In summing up the paper, it is imperative to note that depression is an unexceptional psychological disorder that is characterized with guilt feelings, low self esteem, perturbed sleeping episodes, suppressed mood, lack of appetite, interest or passion as well as inability to concentrate. The actual cause of depression has not been known yet by psychological experts. However, research studies have conclusively demonstrated that females are more likely to encounter depression episodes two times as much as males.

In order to alleviate the effects of depression, antidepressant drugs are recommended for use. For instance, tricyclic antidepressants, serotonin-specific re-uptake inhibitors (SSRIs), Serotonin and Norepinephrine reuptake Inhibitors (SSNIs) and Monoamine Oxidase Inhibitors (MAOIs) are common antidepressants available in the market. Each of this class of antidepressant has a unique mode of action on brain hormones which usually affects an individual’s mood. Finally, antidepressants have both side effects and potential risks to the users. The drugs should be taken with care after receiving advice from a medical expert.

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