A Basic Guide to Antidepressants: Types, Dosage, Side Effects
and Other Helpful Information
Antidepressants are medications used to alleviate depressive symptoms. How do they work? It
depends on the type of antidepressant. Basically, depression medicines alter brain chemistry by
effecting neurotransmitters, the brain’s chemical substances which are responsible for various
functions within the body. For example, some depression drugs increase the neurotransmitter,
Serotonin which is associated with mood (among other things such as sleep, memory, learning to
name a few). Anti-depressant meds are grouped by drug class, which has similar properties and
effects on the brain. Anti-depressants are also used to treat other psychiatric and medical conditions
(see chart below). To obtain medications for depression, you need a prescription from a doctor, which
can be filled at a pharmacy. (There are also natural anti-depressants that don’t require a prescription.
Some popular natural depression remedies include St. John’s Wort and the amino acid 5-HTP.)
The best antidepressant will be prescribed based on many factors such as the symptoms you’re
experiencing, other medicines you’re taking, other medical conditions you have and the antidepressant’s potential side effects.
A common mistake is stopping antidepressant medications without talking to your doctor first. Many
people stop because of side effects and never talk to their doctor about other options. Now there are
many different types of medicine for depression. Sometimes it may take several tries to find the right
anti depression medication for you. There are also other medications that can be taken to lessen side
effects. So, it is important to work with a doctor who is knowledgeable or specializes in prescribing
drugs for depression. For instance, it may be better to see a psychiatrist, a doctor who specializes in
treating mental disorders than a general physician.
Another common error is not giving the depression medication a chance to work and stopping too
soon. It can take several weeks or more before you will notice a positive difference from using antidepressant drugs. Most side effects will stop or lessen with continued use. Some people may
experience many, some or very few of the potential side effects associated with a particular antidepressant.
Myths about antidepressant medicines include they will change your personality, deaden your feelings
or make you feel numb. If these do occur, see you doctor. It may be from the depression or you may
not be on the right medication or the dose may be incorrect.
It is important to discuss with your doctor if you are trying to get off (or switch) your antidepressant
medication. Your doctor can help you taper off slowly and minimize any adverse effects. For example,
some drugs prescribed for depression are short acting or have a short-half life (i.e. remain in your
body for a short time) and as a result people may experience withdrawal symptoms or SSRI
discontinuation syndrome (see below) when stopping too quickly.
There has been concern regarding increased suicide risk and worsening of depression with
antidepressant use among children. Short-term studies have shown a greater risk of suicidal thinking
and behavior among children who use antidepressant medication during the first few months of
treatment. Upon starting depression medicine or a change in dosing, children should be carefully
monitored for any unusual behavior, increase in depressive symptoms or suicidal thinking and
behavior. Similarly, adults with depression and other psychiatric illnesses (and a history of suicidal
behavior) should also be closely monitored.
Below are the different types of depression medication, broken down by drug class. The list of antidepressants includes antidepressant names (brand / manufacturer & generic), typical daily dosage for
an adult, potential antidepressant side effects and other common uses3. The information provided
pertains to adults and not children.
Types of Anti-depressants
Selective Serotonin Reuptake Inhibitors (SSRIs)
SSRI medications change brain chemistry by increasing the neurotransmitter, Serotonin. This increase
is accomplished by blocking the process (which is called reuptake) by which Serotonin is eliminated.
They are the most popular class of antidepressant drugs that are prescribed because of their lower
adverse effects and safety (higher toxic dose) compared to other types of depression medicine. SSRIs
are also considered depression anxiety medications because they treat anxiety among other mental
conditions. Overall, these anti-depressant drugs are not prescribed for treating manic depression
(which is characterized by episodes of depression and/or extreme elevated mood or irritability).
For some SSRI medication, especially ones (e.g. Paxil, Zoloft, Effexor) that remain in the body for a
short time, can cause a set of withdrawal symptoms called SSRI discontinuation syndrome when these
anti-depressant medicines are stopped or decreased. When this occurs, you may feel like you have the
flu and experience symptoms like fatigue, nausea, chills, diarrhea, headache, vomiting and dizziness.
These symptoms will vary in intensity and may last from one to seven weeks.
Anti-depressant
Brand Name(s)
(Manufacturer)
Celexa
(Forest Laboratories)
Anti-depressant
Generic Name
Citalopram
Typical Daily
Dosage Range1
(Adult)
20-40 mg
Anti-depressant
Potential Side Effects2
Nausea, dry mouth, drowsiness,
insomnia, increased sweating,
tremor, diarrhea, decrease in
sexual ability
Other Common Uses: Social Anxiety, Posttraumatic Stress Disorder (PTSD), Premenstrual Dysphoric
Disorder (PMDD), Panic, Obsessive Compulsive Disorder (OCD)
Lexapro
(Forest Laboratories)
Escitalopram
10-20 mg
Nausea, insomnia, change in
sexual desire / decrease in sexual
ability, drowsiness, increased
sweating, fatigue
Other Common Uses: Generalized Anxiety Disorder (GAD), Social Anxiety, PTSD, PMDD
Prozac / Serafem
(Eli & Lilly)
Fluoxetine
20-80 mg
Nausea, insomnia, drowsiness,
anxiety, nervousness, weakness,
decreased appetite, tremor, dry
mouth, sweating, change in sexual
desire / decrease in sexual ability,
diarrhea, akathisia (i.e. inner
restlessness), irritability, hostility
Other Common Uses: OCD, Panic, Bulimia, PMDD, PTSD, Social Anxiety, Anxiety
Luvox4
Fluvoxamine
(Solvay Pharmaceuticals)
50-300 mg
Nausea, headache, drowsiness,
insomnia, nervousness, tremor,
upset stomach, decreased
appetite, dry mouth, vomiting,
weakness, change in sexual desire
/ decrease in sexual ability,
sweating
Other Common Uses: OCD, Social Anxiety, PTSD, PMDD, Panic
Paxil / Pexeva
(Glaxo Smith Kline) /
(Synthon
Pharmaceuticals)
Paroxetine
20-60 mg
Weakness, sweating, nausea,
decreased appetite, drowsiness,
dizziness, insomnia, tremor,
nervousness, change in sexual
desire / decrease in sexual
ability,dry mouth, constipation
Other Common Uses: Panic, Social Anxiety, OCD, PTSD, GAD, PTSD, Anxiety, PMDD
Zoloft
(Pfizer)
Sertraline
50-200 mg
Dry mouth, insomnia, change in
sexual desire / decrease in sexual
ability, diarrhea, nausea,
drowsiness, headache, dizziness,
tremor, upset stomach, sweating
Other Common Uses: Panic, OCD, PTSD, Social Anxiety, PMDD, GAD, Anxiety
Tricyclic Anti-depressants (TCAs)
A class of anti depression drug that is named after its chemical structure (a three ring molecular core).
In addition to increasing levels of Serotonin, TCAs affect Norepinephrine, Dopamine and to varying
degrees Acetylcholine and Histamine. In the past, these depression pills were the first choice in
treating depression until SSRIs and new antidepressant medications were developed. These antidepressants are prescribed less often because they have more unpleasant side effects than SSRI
medications and some are potentially dangerous such as a lower toxic/lethal dose and effects on the
heart. Tricyclics are often prescribed when someone is experiencing resistant depression or not
responding to SSRI meds.
Because its effect on the neurotransmitters Histamine and Acetylcholine, Tricyclic medicines can cause
drowsiness and anticholinergic side effects which include dry mouth, rapid heartbeat, blurred vision,
constipation and difficulty urinating. TCA medication use in the elderly should be done with caution
because of these adverse effects and others such as confusion, delirium and sedation. Overall, this
class of anti-depressants have similar side effects, but differ in terms of level of sedation and
anticholinergic side effects (see table below).
Example of Potential Side Effects2: dry mouth, sedation or drowsiness, blurred vision, rapid heartbeat,
constipation, difficulty urinating, confusion or disorientation, nausea, increased appetite or weight
gain, tremor, dizziness when changing positions, hypotension, weakness, change in sexual desire /
decrease in sexual ability, irregular heart rhythm, headache
Anti-depressant
Brand Name(s)
(Manufacturer)
Anti-depressant
Generic Name
Typical Daily
Dosage Range1
(Adult)
Anti-depressant
Potential Side Effects2,5
Elavil
(AstraZeneca)
Amitriptyline
75-150 mg
High sedation, high anticholinergic
side effects
Ascendin
(WyethAyerst Laboratories
/Lederle Laboratories)
Amoxapine
200-300 mg
Low sedation, moderate
anticholinergic side effects
Anafranil (Mallinckrodt
Pharmaceuticals)
Clomipramine
100-250 mg
Low sedation, low anticholinergic
side effects
Desipramine
100-300 mg
Low sedation, low anticholinergic
side effects
Doxepine
150-300 mg
High sedation, high anticholinergic
side effects
75-200 mg
Moderate sedation, moderate
anticholinergic side effects
Other Common Uses: OCD
Norpramin /
Pertofrane
Aventis)
(Sanofi-
Sinequan / Adapin
(Pfizer) / (Lotus
Biochemical)
Other Common Uses: Anxiety
Tofranil (Mallinckrodt
Pharmaceuticals)
Imipramine
Other Common Uses: Enuresis (i.e. bedwetting)
Aventyl / Pamelor
(Eli & Lilly) /
(Mallinckrodt
Pharmaceuticals)
25-100 mg
Moderate sedation, low
anticholinergic side effects
Vivactil / Triptil (Odyssey
Pharmaceuticals) /
Protriptyline
(Merck & Company)
15-60 mg
Low sedation, moderate
anticholinergic side effects
Surmontil
(Odyssey
Pharmaceuticals)
75-200 mg
High sedation, moderate
anticholinergic side effects
Nortriptyline
Trimipramine
Monoamine Oxidase Inhibitors (MAOIs)
MAOIs were the first medicines developed to successfully treat depression. MAOIs are named after an
enzyme (monoamine oxidase) that breaks down neurotransmitters which include Serotonin and
Norepinephrine. Since MAOIs inhibit this break down, the levels of these neurotransmitters are
increased. These depression medications are used to treat severe or atypical depression which is
associated with symptoms such as anxiety, increased sleeping, overeating, weight gain, rejection
sensitivity and temporary improvement in mood in response to positive events. These antidepressants are often prescribed when other depression meds have not been effective.
These medicines are not prescribed as often as SSRIs or TCAs because of serious side effects and
interactions with certain foods. For example, foods containing a high level of tyramine cannot be taken
with MAOIs (e.g. aged cheeses, sour cream, yogurt, cured meats, dry sausages, wine, beer, soy
sauce, banana peel, liver, fava or broad bean pods, anchovies, pickled herring, caviar, yeast extracts
and sauerkraut). MAOI anti-depressants and these foods may interact and increase blood pressure to
dangerous levels. There are many drug interactions (e.g. over-the-counter cold medicines, nasal
sprays) with these antidepressant meds. It is important to inform your doctor about any other
medications you are taking while on MAOIs.
Example of Potential Side Effects2: dietary interactions, headache, insomnia or sleep problems,
change in blood pressure (blood pressure crisis), drowsiness, nausea, dry mouth, constipation, blood
changes/problems, dizziness when changing positions, fluid retention, tremors, change in sexual
ability, weakness, stomach upset or pain, blurred vision, restlessness, urinary problems
Anti-depressant
Brand Name(s)
(Manufacturer)
Anti-depressant
Generic Name
Typical Daily
Dosage Range1
(Adult)
Marplan
(Oxford
Isocarboxazid
Pharmaceutical Services)
20-60 mg
Nardil
(Parke-Davis/Pfizer)
Phenelzine
45-90 mg
Parnate
(Glaxo Smith Kline)
Tranylcypromine
30-60 mg
Other Antidepressant Medicines
These drugs don’t fit in the above categories. These anti-depressants have a combination of different
properties and effects on neurotransmitters. Most of these depression medications also affect
Serotonin and/or Norepinephrine except Wellbutrin, which affects more Dopamine and Norepinephrine
than Serotonin and Eldepryl, which primarily affects Dopamine.
Anti-depressant
Brand Name(s)
(Manufacturer)
Wellbutrin / Zyban
(Glaxo Smith Kline)
Anti-depressant
Generic Name
Bupropion
Typical Daily
Dosage Range1
(Adult)
200-450 mg
Anti-depressant
Potential Side Effects2
Anxiety, insomnia, dry mouth,
headache, dizziness, loss of
appetite/weight loss, tremor,
restlessness, nausea, vomiting,
sweating, constipation, increased
risk of seizure, skin rash, high
blood pressure
Other Common Uses: Quitting Smoking, Attention-Deficit Hyperactivity Disorder, Seasonal Affective
Disorder
Cymbalta
(Eli & Lilly)
Duloxetine
20-80 mg
Nausea, dry mouth, constipation,
decreased appetite, fatigue,
drowsiness, increased sweating,
dizziness, skin rash, blurred vision
Other Common Uses: GAD, Social Anxiety, PTSD, PMDD, Nerve associated pain
Ludiomil
(Novartis
Pharmaceuticals)
Maprotilin
75-225 mg
Drowsiness, upset stomach,
weakness, anxiety, insomnia, dry
mouth, nightmares, decreased
appetite, skin more sensitive to
sunlight, constipation, change in
sexual desire / decrease in sexual
ability, increased sweating, blurred
vision
Other Common Uses: Anxiety, Nerve associated pain
Remeron / Soltab
(Organon)
Serzone4
(Bristol-Myers Squibb)
Mirtazepine
Nefazodone
15-45 mg
Increase in appetite or weight
gain, drowsiness, water retention,
dizziness, headache, drowsiness,
tremor, skin rash
300-600 mg
Drowsiness, nausea, dry mouth,
dizziness, lightheadedness, blurred
vision, skin rash, ringing in ears,
diarrhea, muscle tension,
shortness of breath, insomnia,
headache, vomiting, increased
appetite, tremor, tingling
sensations, constipation, agitation,
flushing
5-10 mg
Nausea, dizziness, stomach pain,
drowsiness, insomnia, mild
headache, dry mouth, diarrhea,
increase in unusual body
movements, vomiting
Other Common Uses: Anxiety, PTSD
Eldepryl
(Somerset
Pharmaceuticals)
Selegiline
Other Common Uses: Quitting Smoking, Parkinson’s Disease
Desyrel
(BristolMyers Squibb)
Trazodone
Other Common Uses: Sleep Aid
150-400 mg
Drowsiness, dry mouth, dizziness,
lightheadedness, nausea, vomiting,
headache, blurred vision,
constipation, diarrhea, low blood
pressure, confusion, muscle aches
Effexor
(WyethAyerst Laboratories)
Venlafaxine
75-375 mg
Weakness, sweating, nausea,
constipation, vomiting, drowsiness,
dry mouth, dizziness, nervousness,
anxiety, tremor, blurred vision,
sexual dysfunction
Other Common Uses: Panic, GAD, Social Anxiety, PTSD, PMDD
Notes:
1.
Some people may take an effective dose that is outside this range. Information for Typical Daily Dosage
Range obtained from “Alphabetical Checklist of Dosages and Uses of 100 Common Psychotropic
Medications“ by Ed Zuckerman, Ph.D. and Dan Egli, Ph.D.
2.
The side effects described give only a sample of the most common and do not comprise a complete
listing. Other less common and rarer adverse effects have not been included. Please consult a
psychiatrist, physician or health care provider for more information. Side effects information was obtained
from the drug’s manufacturer.
3.
Other common uses include FDA approved and anecdotal uses (commonly reported but not officially
studied). Other common uses do not comprise a complete listing.
4.
The manufacturer has withdrawn this anti-depressant. Often the generic version is still available.
5.
Source: “A Primer of Drug Action” by Robert M. Julien, M.D. Ph.D.