Types of antidepressants: characteristics and effects

Mood disorders are, after anxiety disorders, the most prevalent in the population. Within these types of disorder, depression is the best known and frequent.

It is a disorder that causes great problems in practically all the vital areas of the human being, affecting both cognitive, emotional and interpersonal. For this reason its treatment is one of the great objectives of the psychology and psychiatry, developing different types of treatments both at the psychological level and the cognitive behavioral treatment as a pharmacological in the form of antidepressants.

Regarding the latter, research throughout history has produced numerous types of antidepressants in order to produce an improvement in depressive symptoms, avoiding side effects as much as possible.

We will talk about the latter in the following article: what are the different varieties of antidepressants, what characterizes them and what are their side effects.

Remembering concepts: what is depression?

The main purpose of the different types of antidepressants is to treat depression

. Starting from this premise, it is justified to do a little review of what we consider depression. At a clinical level, depression is considered to be that condition in which a sad mood is present (which can be seen as irritable in the case of childhood depression) together with the lack of motivation and pleasure experimentation, along with other symptoms such as sleep or weight problems.

Depressed people tend to present a high level of passivity at the vital level, feeling that they have little control of their lives and frequently appearing feelings of hopelessness. Those who suffer from depression therefore have a high level of negative affect, along with low affect positive and, in general, usually presents a low level of activation both mentally and physiological.

Thus, the different types of professionals who are in charge of working in order to improve the situation of these people They have to find methods and mechanisms that make it possible to face these difficulties, having been created from pharmacology the different types of antidepressants described below.

Main types of antidepressants

Different antidepressants have different mechanisms of action, but the main hypotheses and treatments explain depression from the degradation of monoamines and / or serotonin, with which the antidepressants created are mainly focused on preventing the degradation of these substances and keeping them for longer in the synaptic space.

1. Inhibitors of the enzyme MonoAmino Oxidase or MAOS

They are the first antidepressants discovered. Its action is based, as in other types of antidepressants, on prevent the breakdown of monoamines by targeting a particular enzyme. This enzyme is monoamine oxidase, which is emitted from the presynaptic neuron when it captures an excess of monoamines in the brain synapse in order to eliminate said excess. Thus, eliminating or blocking this enzyme prevents the degradation of monoamines in the synaptic space, having a greater availability of these neurotransmitters.

However this type of antidepressant poses a high risk to health, since in interaction with substances that contain thiamine (a substance that is easily found in a wide variety of foods) can cause hypertensive crisis, along with other side effects unpleasant. For this reason, they are mainly used in cases where other antidepressants have not shown an effect.

Types of MAOS

Within the MAOS we can find two subtypes. The first subtype is irreversible monoamine oxidase inhibitors., whose main mechanism of action is the complete destruction of this enzyme, so that until it is not generated again its basic functionality is lost. This type of antidepressant is the one that presents the greatest risk, being dangerous its interaction with other substances rich in thiamine and having to carefully monitor the food to be consumed to avoid serious problems of Health.

A second subgroup is the reversible inhibitors of monoamine oxidase or RIMA, which are preferable to other types of MAOS because they do not pose such a high risk or tend to interact with the diet. Its operation is based on temporarily inhibiting the function of the enzyme. Moclobemide is one of the substances that are part of this type of antidepressant.

2. Tricyclic and tetracyclic antidepressants

These drugs are, after the MAOS, the oldest and what for a long period of time were the most widely used antidepressants. Its mechanism of action is based on preventing the reuptake of serotonin and noradrenaline. However, its action is nonspecific, affecting other hormones such as acetylcholine, histamine and dopamine. Because of this, it can have serious side effects and even be addictive.

Overdose from these types of substances is life threatening. For these reasons, and given the discovery of new substances, they are no longer as widely used, more can continue to be found in clinical practice due to their greater effect in severe depression.

3. Selective Serotonin Reuptake Inhibitors or SSRIs

Selective serotonin reuptake inhibitors are currently the most widely used type of antidepressant in clinical practice, being the treatment of choice in cases of depression, among other things because the side effects they produce are not as intense as those of other drugs used with the same end.

These are psychotropic drugs that act by specifically inhibiting the reabsorption of serotonin, showing no effects on other neurotransmitters. Although they can produce some side effects, these are usually mild (nausea, vomiting or light sedation between others), are one of the safest classes, being applied in patients who have not had previous contact with antidepressants.

Furthermore, the relationship between depression and anxiety and the specific mechanism of action of the SSRI has also been used as the treatment of choice in some anxiety disorders.

4. Selective Serotonin and Noradrenaline Reuptake Inhibitors or ISRN

This type of antidepressant, its best known exponents being venlafaxine and duloxetine, acts on serotonin and norepinephrine as with tricyclics. The main difference with this other type of antidepressant is in its specificity, that is, while the dual inhibitors of serotonin and norepinephrine has an effect only on these two neurotransmitters, tricyclics have an effect on other substances such as acetylcholine, which can produce effects secondary.

Since they work not only on serotonin but also with norepinephrine, these drugs show a relatively faster effect than other substances.

5. Selective Dopamine and Noradrenaline Reuptake Inhibitor: Bupropion

Although this substance is best known for being very useful in the detoxification of nicotine and other substances, bupropion has been shown to have positive effects in cases of depression, acting by inhibiting the transport of dopamine and norepinephrine.

Risks and side effects

Like all psychoactive drugs, The use of different types of antidepressants can carry various risks and side effects. It must be taken into account that between the first antidepressant administration and its therapeutic action, in general, between two and four weeks because neurons have to undergo a process of adaptation and modification of their receptors, especially in relation to serotonin.

However, the presence of side effects may occur before noticing their therapeutic effects, which is why antidepressant treatment is usually discontinuous and often abandoned. Some of the symptoms and risks of using the different types of antidepressants available are as follows.

Dependence

Some types of antidepressants can generate tolerance and dependence, being an example of this the tricyclics. Likewise, the abrupt cessation of its consumption can generate withdrawal syndromes and rebound effects, being necessary to guide both its consumption and its cessation. That is why sometimes it is not recommended to make a sudden withdrawal from its consumption, but a more gradual one that allows the body to adapt to the new situation.

Overdose

Taking an excessive amount of antidepressants can lead to intoxication and overdose, the latter being able to be lethal Tricyclics are some of the drugs that have registered cases of this phenomenon, a fact to be evaluated when medicating patients with suicidal ideations.

Hypertensive crisis

This type of side effect is one of the biggest risks that MAOS produce. It is due to the interaction of this substance with substances rich in proteins and thiamine, frequent elements in the diet. Thus strict control of diet and blood tests are necessary to prevent problems.

Sexual and genital symptoms

Taking some antidepressants sometimes causes a decrease in the libido of those who take them, decreasing desire or being able to cause situations such as anorgasmia or delayed ejaculation. This occurs because the hormonal imbalance produced by the consumption of these substances is very noticeable in sexual behavior, as it is very sensitive to this type of change.

Drowsiness and sleep problems

Many types of antidepressants cause drowsiness and sedation as a secondary symptom. Others, such as MAOIs, can suppress paradoxical or REM sleep, also producing problems when consolidating new knowledge.

Manic symptoms

Some substances cause you to go from a depressed to a manic state. An example of this is bupropion.

Other somatic and gastrointestinal symptoms

The presence of nausea and vomiting is common with the taking of these substances. as well as headaches and tremors. In fact, these types of symptoms are the most common secondary symptoms during antidepressant use, being generally mild. Many of these alterations appear initially and with the appearance of tolerance to the substance they disappear.

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