Depression isn’t the same for everyone: Multiple types exist, and people experience this treatable illness in varying degrees of severity.
For some people with depression, non-pharmacological interventions like psychotherapy, lifestyle changes, and self-care may be enough to lift the cloud and improve symptoms.
But for many other people, these steps aren’t enough, and medication is needed.
Numerous depression medications are available today. If you’re struggling with depression, talk to your primary care doctor or a mental health professional, such as a psychiatrist, to learn whether an antidepressant may be right for you.
Following is what you need to know about the types of antidepressants.
SSRIs: The Most Frequently Prescribed Antidepressants
Selective serotonin reuptake inhibitors (SSRIs) are the most commonly prescribed anti-depressant class.
Although it’s not clear how SSRIs treat depression, these drugs are known to inhibit the uptake of serotonin (a kind of chemical messenger called a neurotransmitter that helps regulate mood).
This means they prevent the body from breaking down serotonin, which in turn helps increase levels of this neurotransmitter in the body.
The following SSRIs are approved by the FDA to treat depression:
- Citalopram (Celexa)
- Escitalopram (Lexapro)
- Fluoxetine (Prozac, Sarafem, Symbyax)
- Paroxetine (Paxil, Paxil CR, Pexeva)
- Sertraline (Zoloft)
- Vilazodone (Viibryd)
- Vortioxetine (Trintellix)
The most common side effects of SSRIs include:
- Nausea and vomiting
- Dry mouth
- Weight changes, more commonly weight gain
- Diarrhoea
- Drowsiness
- Sexual problems
- Headache or dizziness
- Drowsiness or insomnia
- Agitation, restlessness, or nervousness
SNRIs Work by Blocking Reuptake of Two Brain Chemicals
Another class of anti-depressants, serotonin and norepinephrine reuptake inhibitors (SNRIs), block the reabsorption of the neurotransmitters serotonin and norepinephrine, making them more available to your brain.
SNRIs that are approved by the FDA to treat depression include:
- Duloxetine (Cymbalta)
- Venlafaxine (Effexor, Effexor XR)
- Levomilnacipran (Fetzima)
- Desvenlafaxine (Pristiq)
The most common side effects of SNRIs include:
- Dizziness
- Dry mouth
- Excessive sweating
- Headache
- Nausea
Other possible side effects of SNRIs are:
- Constipation
- Insomnia
- Loss of appetite
- Sexual dysfunction
- Tiredness
Cyclic Antidepressants: Prone to Causing Side Effects
Tricyclic and tetracyclic anti-depressants are older drugs that work by blocking the reabsorption of serotonin and norepinephrine through a different mechanism than SNRIs.
These drugs are not widely used today because they can cause a range of side effects, some of which may be serious, such as disorientation or confusion, but they are sometimes prescribed when other anti-depressants don’t work.
Examples of FDA-approved tricyclics are:
- Amoxapine (Asendin)
- Amitriptyline (Elavil)
- Nortriptyline (Aventyl, Pamelor)
- Desipramine (Norpramin)
- Doxepin (Sinequan, Silenor)
- Imipramine (Tofranil)
- Protriptyline (Vivactil)
- Trimipramine (Surmontil)
The tetracyclic maprotiline (Ludiomil) is also approved by the FDA for the treatment of depression.
Common side effects of cyclic anti-depressants include:
- Blurred vision
- Constipation
- Drop in blood pressure that can cause light-headedness when going from a seated position to a standing position
- Drowsiness
- Dry mouth
- Urine retention
MAOIs: The Oldest Anti-depressants
The oldest class of anti-depressants, monoamine oxidase inhibitors (MAOIs), works by blocking the enzyme monoamine oxidase, which breaks down various neurotransmitters in the brain, including serotonin, norepinephrine, and dopamine.
Examples of MAOIs include:
- Selegiline (Emsam), a skin patch that may cause fewer side effects than MAOIs taken by mouth
- Isocarboxazid (Marplan)
- Phenelzine (Nardil)
- Tranylcypromine (Parnate)
Although MAOIs can sometimes help people with depression that does not respond to other anti-depressants, they are not widely used today because of their potential side effects and interactions with certain foods and beverages as well as other drugs.
For example, for people taking MAOIs, ingesting large amounts of the compound tyramine (found in aged cheeses, cured meats, draft beer, sauerkraut, and fermented soy products like miso, tofu, and soy sauce) could cause your blood pressure to rise to a dangerously high level.
You may also experience serious reactions if you take an MAOI with various medications, including:
- Other prescription antidepressants
- Certain pain relievers
- Cold and allergy drugs
- Herbal supplements
On rare occasions, MAOIs and other serotonin-containing drugs can cause a potentially life-threatening condition called serotonin syndrome. You may be at risk if you take too much of a serotonin-containing anti-depressant or if you combine an MAOI with another prescription anti-depressant, certain pain or headache medications, or St. John’s wort (a herbal supplement sometimes used for depression).
Atypical Antidepressants: Unique Medications That Work in Different Ways
Medications that don’t fit into the classes listed above may also treat depression by altering levels of different neurotransmitters in the brain.
A well-known medication called bupropion (Wellbutrin) targets norepinephrine and dopamine and is categorised as a norepinephrine-dopamine reuptake inhibitor. This anti-depressant causes fewer sexual side effects than many other antidepressants.
Other so-called atypical medications include:
- Trazodone (Desyrel)
- Nefazodone (Serzone)
- Mirtazapine (Remeron)
- Vilazodone (Viibryd)
For most atypical anti-depressants, the most common side effects include:
- Blurry vision
- Constipation
- Dizziness
- Drowsiness
- Dry mouth
N-Methyl D-Aspartate (NMDA) Receptor Antagonists May Offer Quicker Relief
While many traditional anti-depressants affect levels of serotonin, norepinephrine, or dopamine, a newer class of anti-depressants called NMDA receptor antagonists work by helping maintain the balance of glutamate and gamma-aminobutyric acid (GABA).
These two neurotransmitters have opposite actions in the body, and the brain typically functions best when they’re balanced.
NMDA receptor antagonists can help people whose symptoms haven’t improved with typical treatments and usually offer more rapid relief than most anti-depressants.
The FDA recently approved the following NMDA antidepressants:
- Esketamine (Spravato), a nasal spray that’s used in combination with an oral antidepressant
- Dextromethorphan-bupropion (Auvelity)
Common side effects of Spravato may include:
- Dissociation or feeling drunk
- Dizziness
- Feelings of anxiety
- Lack of energy or drowsiness
- Increased blood pressure
- Nausea or vomiting
- Decreased sensations of touch or other senses
Common side effects of Auvelity could include:
- Dizziness
- Diarrhoea
- Drowsiness
- Dry mouth
- Excessive sweating
- Headache
- Sexual problems
Neuroactive Steroids: Another Fast-Acting Option
Neuroactive steroids are a newer class of medicines that are thought to work by affecting levels of the neurotransmitter GABA in the body.
Like NMDA receptor antagonists, they tend to work more quickly than most other anti-depressants.
The FDA recently approved the following neuroactive steroids for postpartum depression:
- Brexanolone (Zulresso), a continuous infusion administered under medical supervision
- Zuranolone (Zurzuvae)
Zulresso is administered over 2.5 days by a healthcare provider in a certified healthcare facility. It’s only available under a special program because of the side effects it can cause.
The most common ones are:
- Dry mouth
- Flushing
- Loss of consciousness
- Tiredness or sedation
Zurzuvae is an oral medication to be taken with a fat-containing meal once daily in the evening for 2 weeks. The most common side effects of Zurzuvae include:
- Burning or pain while urinating
- Cold symptoms like sneezing, sore throat, or stuffy nose
- Diarrhoea
- Dizziness
- Weakness, tiredness, or drowsiness
Serotonin Receptor Agonists: A New Antidepressant Class
A new class of antidepressants called serotonin receptor agonists are believed to work by targeting certain serotonin receptors, such as the 5-HT1A receptor in the brain. These receptors help regulate mood and emotions.
The FDA recently approved the serotonin receptor agonist gepirone ER (Exxua) to treat depression.
The most common side effects of Exxua are:
- Dizziness
- Headache
- Nausea
- Sleep problems
- Stomach pain and upset
Atypical Antipsychotics: Approved for Use With Antidepressants
Atypical antipsychotics aren’t considered anti-depressants. However, several atypical antipsychotics are FDA-approved to treat depression in combination with anti-depressants. Doctors sometimes prescribe these drugs to people whose depression hasn’t improved with other treatments. They include:
- Brexpiprazole (Rexulti)
- Aripiprazole (Abilify)
- Cariprazine (Vraylar)
- Quetiapine (Seroquel XR)
- Fluoxetine And Olanzapine (Symbyax)
Common side effects of atypical antipsychotics, especially when taken long-term, include:
- Weight gain
- Metabolic dysfunction
- Extrapyramidal symptoms (involuntary movements)
- Tardive dyskinesia
Antidepressant Safety and Side Effects
Most anti-depressants are generally safe, but some people – especially children, teenagers, and young adults under age 25 – may experience an increase in suicidal thoughts, especially during the first few months of treatment or when their dosage goes up or down.
If this happens to you or someone you know, immediately contact a doctor or seek emergency help by contacting the Lifeline 13 11 14 or, if the risk is imminent, call 000.
As mentioned, many anti-depressants come with side effects, which can vary by type. They usually improve after a couple weeks, but if they don’t, let your doctor know. Your doctor could change the timing or dosage of your anti-depressant to help lessen side effects, or they may switch you to another anti-depressant and see if that works better for you.
Once you’ve begun taking anti-depressants, don’t stop without your doctor’s assistance; discontinuing the medication too soon means your depressive symptoms might come back. When the time is right, your doctor can help you gradually taper your usage.
The Takeaway
Although some people with depression fare well with only non-pharmacological treatments, others may also need anti-depressant medication to feel better. There are many different options, and certain medicines work better for some people than others. Work closely with your doctor to find the best option for you, and tell them about any side effects you’re having.
Additional reporting by Pamela Kaufman and Christina Vogt.
SOURCE: Neuroscience News
