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Antidepressants in general

What are antidepressants?

The word "Antidepressant" is a trade name that applies to a wide range of chemically different classes of drugs that act in different ways on the body and brain. (Source: )
There are 6 families of antidepressants: tricyclic and heterocyclic (ATC) monoamine oxidase inhibitors (MAOIs), selective serotonin reuptake inhibitors  (SSRIs), selective serotonin and norepinephrine reuptake inhibitors (SSRIs), antidepressants of various classifications: bupropion (Remeron) and mirtazapine (Wellbutrin, Zyban) and vortioxetine (Trintellix), multimodal antidepressant. Consult the list of antidepressants by family.  (Source AGIDD-SMQ)

Antidepressants are prescribed to treat people diagnosed with a wide variety of depressive, anxiety, obsessive-compulsive, eating, post-traumatic stress disorder, and attention, sleep disorders, and many other conditions. The United States Food and Drug Administration (FDA) has not approved most of these drugs for use in treating people diagnosed with most of these conditions, but some doctors and psychiatrists prescribe the drugs for these conditions "outside MA". (When a physician prescribes a drug for a use that has not been approved by the FDA and is not listed on the drug's official label, the physician is prescribing "off label".) (Source: https://

The mechanism of action of antidepressants essentially consists in inhibiting the reuptake of norepinephrine, serotonin or even dopamine. 

How soon should the effect start to be felt? How will I know?
It takes several weeks for antidepressants to produce their full effects. Improvements in sleep, appetite, and energy are often early warning signs that the drug is working. Mood improvement usually shows up later. (CAMH, Antidepressants, Online, accessed June 14, 2021, )

Antidepressants are habit-forming and cause withdrawal effects when withdrawn, more so when the withdrawal is abrupt.
(CAMH, Antidepressants, Online, accessed June 14, 2021, )

Withdrawal symptoms

Withdrawal symptoms usually appear one to seven days after a discontinuation or a significant reduction in dose. 

About 55% of people feel as if they are going through a period of excitement or depression which is accompanied by raw emotions, anxiety, disturbing dreams and lethargy (numbness of being) temporary. These effects disappear within a few days.

Selective serotonin reuptake inhibitors or SSRIs (Prozac, Luvox, Zoloft, Paxil and Celexa), serotonin and norepinephrine reuptake inhibitors or SNRIs (Effexor, Cymbalta and Pristiq) and bupropion share these symptoms weaning:  

Main psychological withdrawal symptoms:

  • Anxiety 

  • Irritability 

  • Hustle 

  • Insomnia 

  • Nightmares or dreams of intense realism (vivid)  

Very rarely :

  • Suicidal tendencies or tendencies to want to harm themselves which can appear suddenly at the time of increases or reductions. These symptoms are often preceded by a period of severe agitation (akathisia).

  • Mania or hypomania  

Main physical withdrawal symptoms:  

  • Flu-like effects: 

  • Headaches (headaches) 

  • sweating 

  • Fatigue 

  • General malaise 

  • Muscle aches 

  • Diarrhea 

  • Dizziness, vertigo 

  • Tremors 

  • Numbness or tingling of the extremities 

  • Electric shock sensations in the limbs 

  • Blurry vision 

  • Very rarely: 

  • Concentration or memory problems 

  • Movement disorders  

Effexor and Paxil have shorter durations of action than other antidepressants. They can give withdrawal reactions that are more difficult to control from day one. It is therefore even more important to gradually reduce the dose.

(Source: AGIDD-SMQ RRASMQ, ERASME, My GAM personal guide, 2017, p.116-117)


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