Antidepressant: Selective Serotonin Reuptake Inhibitor (SSRI)

Antidepressant: Selective Serotonin Reuptake Inhibitor (SSRI)

What Are Antidepressants?

Anti-depressants are a wide range of medications that are used to treat depression (see blog post: What Is Depression? And Do I Have It?) as well as other health conditions.

They are prescribed to help compensate for any chemical imbalances in the brain that are believed to be responsible for changes in mood and behavior (see blog post: Treating Depression With Anti-Depressants)

According to statistics, women are twice as likely as men to take antidepressant medication (16.5 percent compared with 8.6 percent). Women are more likely than men to take antidepressants in every age group (1)

During 2011–2014, 12.7% of persons aged 12 and over, 8.6% of males, and 16.5% of females took antidepressant medication in the past month (2).

There are 5 Types of Antidepressants:

  1. Selective Serotonin Reuptake Inhibitors (SSRIs)
  2. Serotonin and Noradrenaline Reuptake Inhibitors (SNRIs)
  3. Tricyclic Antidepressants (TCA)
  4. Monoamine Oxidase Inhibitors (MAOIs)
  5. Noradrenaline and Specific Serotoninergic Antidepressants (NASSAs)



In this post, I will discuss the most commonly prescribed anti-depressant: The SSRI.

But First, Serotonin!

Serotonin, also known as 5-hydroxytryptamine (or 5-HT), is a neurotransmitter that is known to influence and regulate our mood.

It is believed to be involved in several psychological activities such as appetite, digestion, sleep, memory, sexual desire, happiness, and well being(2).

In retrospect, someone who has low levels of serotonin may show an increase in feelings of sadness, anxiety, and worthlessness.

This is why research has suggested that there is a link between serotonin and depression. However, it is still unclear if whether depression is due to low levels of serotonin or if depression causes a fall in serotonin levels (3).

Treating Serotonin Deficiency With SSRI’s

SSRI’s are the most prescribed type of anti-depressant and have been used since the 1980s.What’s In A Name: Dissecting the role of SSRI’s

Selective — Because they only affect serotonin and not any other neurotransmitter.Serotonin — the neurotransmitter that is known to help regulate mood and social behaviors, appetite and digestion, and sleep.Reuptake — the absorption by a presynaptic nerve ending of a neurotransmitter that is has secreted.Inhibitor — Because they inhibit the uptake of serotonin to make it more available.

SSRI’s treat depression by increasing levels of serotonin in the brain by preventing the reuptake into neurons. This allows serotonin to be more readily available for proper message transmission between neurons (4)

SSRI Medication List

The following are SSRI’s that are approved by the Food and Drug Administration (FDA) to treat depression (5):

  • Citalopram (Celexa)
  • Escitalopram (Lexapro)
  • Fluoxetine (Prozac)
  • Paroxetine (Paxil, Pexeva)
  • Sertraline (Zoloft)



You may be thinking, why are there several different medications for SSRI’s?

Although all SSRIs work, in a similar way, each SSRI may differ in potency and in how fast the body is able to eliminate the drug.

It’s possible that if one SSRI does not work for someone a medical professional can prescribe different SSRIs to the patient, all dependent on the patient’s response to that antidepressant.SSRI’s Have Their Own Side-Effects

The main reason why people take any kind of medication is to resolve some type of health issue. However, medications are not perfect and most of the time they can solve an issue but not without consequence.

Like with many anti-depressants SSRI’s can have side-effects such as (6):

  • Nausea
  • Insomnia
  • Anxiety
  • Restlessness
  • Decreased sex drive
  • Dizziness
  • Weight gain
  • Tremors
  • Excessive sweating
  • Sleepiness or fatigue
  • Dry mouth
  • Diarrhea
  • Constipation
  • Headaches

In conclusion…

Depression is a complex mental illness that is not the same for every person. (see blog post: Understanding the Difference Between Mental Health and Mental Illness )

Although antidepressants are typically prescribed for depression, it is possible that treatment doesn’t require the administration of antidepressants.

But rather, antidepressants in combination with other therapies can help.

It is still unknown if low serotonin levels cause depression or if depression results in low serotonin levels.

To combat in low serotonin levels SSRIs prescribed to increase the presence of serotonin.

Lastly, antidepressants are not the ultimate solution to resolve depression. Rather, it is a way to manage it chemically.


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