Antidepressants are a class of medications that reduce symptoms of depressive disorders by correcting chemical imbalances of neurotransmitters in the brain.

What are antidepressants commonly prescribed for?

How do antidepressants work?

Antidepressants can increase the concentration of chemical messengers in the brain (serotonin, dopamine, norepinephrine) that play a part in managing a person’s mood, feelings and thoughts.

Each class of antidepressant targets one or more type of chemical messenger to help improve mood, feelings and thoughts.

What antidepressants are currently available?

The most commonly prescribed group of antidepressants are selective serotonin reuptake inhibitors which include:

  • Citalopram (Celexa)
  • Fluoxetine (Prozac)
  • Paroxetine (Paxil)
  • Sertraline (Zoloft)
  • Escitalopram (Lexapro)
  • Fluvoxamine (Luvox)

Other antidepressants include the following:

  • Bupropion (Wellbutrin)
  • Venlafaxine (Effexor)
  • Desvenlafaxine (Pristiq)
  • Duloxetine (Cymbalta)
  • Trazodone (Desyrel)
  • Mirtazapine (Remeron)
  • Desipramine (Norpramin)
  • Amitriptyline (Elavil)
  • Nortriptyline (Aventyl)
  • Imipramine (Tofranil)
  • Doxepin (Sinequan)
  • Trimipramine (Surmontil)
  • Maprotiline (Ludiomil)
  • Moclobemide (Manerix)
  • Phenelzine (Nardil)
  • Tranylcypromine (Parnate)

What can I expect from antidepressants?

Signs that the medication may be helping can include improvements in:

  • Mood
  • Sleep
  • Appetite
  • Wanting to be more active
  • Having more motivation
  • Thoughts being more clear
  • Less feelings of guilt, hopelessness, worthlessness

While antidepressants can’t fix the environmental circumstances that cause situational depression, they can reduce your symptoms enough to enable you to pursue and receive more benefits from lifestyle changes, support groups, and counselling techniques.

How long does it take antidepressants to work?

It may take up to two months to know if the medication is working for you. In the first few days, you may notice improvements in your sleep and appetite, and may experience reduced restlessness, anxiety and agitation; however, it can take up to one month before you experience a noticeable improvement in mood, feelings and thoughts.

Medications may work differently in each person because everyone’s brain is wired differently.

Finding the right antidepressant is a process of trial and error. Many people have to try several different medications before they find one that works.

How long do individuals need to continue taking antidepressants?

Individuals experiencing their first episode of mental illness usually need to continue to take their antidepressants for 6 to 12 months. Individuals who have experienced two or more episodes of mental illness may need to use antidepressants for two to five years or longer.

It is important not to stop taking your medication until you have talked to your doctor as this can cause serious withdrawal effects.

What are the common side effects of antidepressants?

Not everyone will experience side effects. Many side effects will go away with time as your body gets used to the medication.

Some common side effects may include:

  • Restlessness, anxiety
  • Drowsiness or difficulty sleeping
  • Headache
  • Stomach problems – nausea, diarrhea, constipation
  • Dry mouth
  • Dizziness

If at any time you develop a sudden rash, have any trouble with breathing, sudden pain in any part of the body (e.g. chest, muscles), trouble staying awake during the day or difficulty peeing, please contact your doctor immediately.

Some side effects may resolve over time but you should always report any symptoms that you feel are bothersome and/or have become worse.

What can I do to help reduce the side effects?

Some suggestions to help reduce risk and/or severity of side effects can include:

  • Balanced diet, adequate fluids, daily activity or exercise
  • Report any weight gain ≥ 5 per cent (2 to 25 lbs)
  • Limit excess intake of caffeinated products, sodium
  • Smoking management

Sometimes a change in dosing schedule may help manage some side effects. You should follow up with your health care provider as there may be other treatments that could help.

Your health care provider may also ask you to go for lab work or other tests to make sure you are tolerating the medication and watch for any concern of side effects.

How can I safely use my antidepressant?

Do not take any other medication that is not prescribed by your doctor (e.g. over the counter products, vitamins, herbal supplements) without checking if it is safe to take with your antidepressant. Check with your pharmacist before deciding to take anything new.

All antidepressants should be taken regularly, preferably at around the same time every day. If you miss a dose, do not double up; take the next dose at the regularly scheduled time.

Do not stop taking your antidepressant until you have spoken with your doctor. If there is a need to stop, it is best to gradually reduce your dose over time.


  • HealthLink BC: Antidepressants
    Get more information about antidepressants. 
  • Here to Help: Myths about antidepressants
    Although antidepressants are among the most widely prescribed of all medications, many people considering them as a treatment option still have many fears and questions. This resource addresses myths and facts regarding antidepressants.