What Are Antidepressants?

Antidepressants are prescription medications used to treat moderate to severe depression and other mental health conditions, including obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD), and generalized anxiety disorder.

The most common forms of antidepressants are selective serotonin reuptake inhibitors (SSRIs) and serotonin and norepinephrine reuptake inhibitors (SNRIs).

Common antidepressants include:

  • Fluoxetine (Prozac)
  • Escitalopram (Lexapro)
  • Paroxetine (Paxil)
  • Sertraline (Zoloft)
  • Duloxetine (Cymbalta)

Studies show that in the US, in 2018, 13.2% of adults aged 18 and older had used antidepressant medications in the past 30 days. Use was higher among women (17.7%) than men (8.4%).

How Do Antidepressants Work?

Antidepressants work by increasing specific chemicals in the brain, known as neurotransmitters. Serotonin and norepinephrine are the two primary neurotransmitters that affect mood and happiness. Serotonin significantly regulates mood and is often called the “happy hormone,” while norepinephrine plays a role in mood, arousal, and attention.

Because it takes a while to increase and build up the amounts of these neurotransmitters in the brain, it can take 4-6 weeks before a person starts to feel the effects of their medication initially.

It is essential to be patient and not quit taking your medication because you are not feeling the desired results right away.

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Types Of Antidepressants


Selective serotonin reuptake inhibitors (SSRIs) are the most commonly prescribed type of antidepressant. As their name suggests, they regulate the amount of serotonin in the brain by preventing it from metabolizing, thereby increasing the amount. They are usually preferred over other antidepressants because they have fewer side effects.

SSRIs include:

  • Fluoxetine (Prozac)
  • Sertraline (Zoloft)
  • Paroxetine (Paxil)

  • Fluvoxamine (Luvox)
  • Citalopram (Celexa)
  • Escitalopram (Lexapro)


Serotonin-norepinephrine reuptake inhibitors (SNRIs) similarly boost mood by interacting with serotonin and norepinephrine in the brain.

SNRIs include:

  • Desvenlafaxine (Pristiq, Khedezla)
  • Duloxetine (Cymbalta, Irenka)
  • Levomilnacipran (Fetzima)
  • Milnacipran (Savella)
  • Venlafaxine (Effexor XR)


Tricyclic antidepressants (TCAs) inhibit the reuptake of serotonin and norepinephrine. They are no longer usually recommended as the first treatment for depression because they can be more dangerous if an overdose occurs. They also cause more unpleasant side effects than SSRIs and SNRIs.

However, TCAs are sometimes used for people with severe depression who fail to respond to other treatments. TCAs may also be recommended for other mental health conditions, such as OCD, bipolar disorder, and nerve pain.

TCA antidepressants include:

  • Amitriptyline
  • Amoxapine
  • Desipramine (Norpramin)
  • Doxepin

  • Imipramine (Tofranil)
  • Nortriptyline (Pamelor)
  • Protriptyline
  • Trimipramine


Wellbutrin (bupropion) belongs to a class of medications called aminoketones. It works by increasing your levels of dopamine and norepinephrine. Unlike SSRIs and SNRIs, it does not act on serotonin and does not contribute to antidepressant discontinuation syndrome, which occurs when a person suddenly stops taking their medication.

What Are The Side Effects Of Antidepressants?

Common side effects of SSRIs and SNRIs include:

  • Feeling agitated, shaky, or anxious
  • Indigestion and stomach aches
  • Diarrhea or constipation
  • Loss of appetite
  • Dizziness

  • Fatigue or difficulty sleeping
  • Headaches
  • Decreased sex drive
  • Difficulties achieving orgasm
  • Difficulties obtaining or maintaining an erection

Common side effects of TCAs include:

  • Dry mouth
  • Blurring of vision
  • Constipation
  • Problems urinating

  • Drowsiness
  • Dizziness
  • Weight gain
  • Heart palpitations or fast heartbeat

These side effects often improve within a few weeks, so if you are experiencing some of these side effects, you should not stop taking the medication. Instead, talk with your doctor.

How Are Antidepressants Taken?

Antidepressants are usually taken in tablet form and often take 2-4 weeks to work.

Most prescribers will follow the general rule of starting with the lowest possible dose thought necessary to improve your symptoms. Still, if you are not feeling any improvement in mood after four weeks, your doctor may recommend increasing the dose or trying a different medication. Sometimes, it takes a couple of tries to determine the correct dosage and medication that works best for you.

Typical Doses Of Antidepressants

There is no “typical dose” as each antidepressant is different, and each person will react differently to different dosages and different medications. Therefore, dosages often vary. For example, 20mg of citalopram can be considered an optimal daily dose, whereas 50mg of sertraline can be considered optimal.

However, the efficacy of the antidepressant can max out, meaning that you are on the highest dose for the most benefits. It is possible to add another antidepressant from a different class to your current antidepressant regimen, but this is done with careful consideration and monitoring from your doctor.

What Is Antidepressant Discontinuation Syndrome?

Often, people will be on antidepressants long-term (for years) and tolerate some side effects. However, if you want to stop taking antidepressants, it should not be done prematurely or without a thorough discussion with your doctor because your depression can re-emerge.

If you and your doctor agree to stop antidepressants, your doctor may slowly wean you off the medication to prevent discontinuation syndrome.

Coming off antidepressant medication can cause antidepressant withdrawal and can set you up for a relapse of depression. However, there is a difference between withdrawal (also called antidepressant discontinuation syndrome) and depression relapse.

About 20% of people develop antidepressant discontinuation syndrome following an abrupt stoppage of or marked reduction in the dose of an antidepressant after taking it for one month. Discontinuation symptoms can include anxiety and depression, which mimics depression relapse.

Discontinuation syndrome also includes physical symptoms such as:

  • Flu-like symptoms
  • Insomnia
  • Nausea
  • Dizziness
  • Abnormal sensations such as tingling and shock-like feeling
  • Hyperarousal symptoms such as irritability, aggression, and reactivity

Discontinuation syndrome happens days to weeks after stopping the antidepressant, and symptoms eventually go away.

In contrast, a relapse:

  • Happens a few weeks after stopping antidepressants
  • Lasts over one month
  • Results in worsened depression symptoms

Having discontinuation symptoms doesn’t mean you’re addicted to your antidepressant. A person who is addicted craves the drug and often needs increasingly higher doses. Few people who take antidepressants develop a craving or feel a need to increase the amount.

Alternative Options To Antidepressants

Antidepressants, regardless of the class, do carry side effects, and each person reacts differently.

Some people switch to another antidepressant with a longer half-life to gradually lower the dosage before stopping medication completely. While this works for some, it’s important to note that only certain practitioners, like psychiatrists and primary care physicians, can prescribe medication.

If you are struggling with depression and choose not to use antidepressants or would like to taper off of medication completely, psychotherapy can be an equivalent option, depending on your symptoms and severity. Psychotherapy is often the first-line, non-pharmacological treatment for depression.

Online therapy provides support for those struggling with depression by connecting them with licensed therapists, who utilize different psychotherapy approaches, such as CBT and DBT, to address and treat depressive symptoms. Many people benefit from this form of treatment. If you are interested in the options available to you, explore our online therapy directory today.