Nearly 1 in 10 of Americans currently take an antidepressant, with millions more considering them as they become an increasingly viable way to address depression. Antidepressants are proven to help regulate mood and relieve symptoms of depression. In fact, a meta-analysis by Oxford University concluded that of 21 common antidepressants studied, all 21 antidepressants were more effective than placebo medications in treating major depression.


If you’re someone who is considering or already taking medication, it’s important to know things like what an SSRI is, how they metabolize in your body, and how they actually help you get better. While your doctor will certainly be able to help you select the right antidepressant(s), dosage, and treatment plan, it’s a good idea to be an informed consumer about your medication.


Here, you can get a basic overview of what antidepressants are and how they might affect your body. We hope you can use this information to better inform your mental health journey!



What are antidepressants?


Before we can understand how antidepressants work, let’s first lay out what we know about how depression itself works. We know that there are three factors that can commonly lead to depression: genetics, chemical imbalances in the brain, and mood dysregulation. Any combination of these factors, or even less common ones such as stressful life events, can lead to depression.


So, how are antidepressants supposed to help? 


The most common types of antidepressants are reuptake inhibitors, which essentially work to boost the activity of neurotransmitters. These neurotransmitters (e.g. serotonin or dopamine) pass between cells in the brain as a way of communicating information, and are involved with determining your mood and behavior. Many scientists believe that by improving mood regulation, antidepressants can lead to symptom relief.


Neurotransmitters are released all the time to help deliver information between brain cells. After releasing the neurotransmitters, the cells then reuptake, or reabsorb, these chemicals so that they can be used again. 


There has been a ton of research to show that increasing neurotransmitter activity can help counter the symptoms of depression, anxiety and other mental health conditions. These antidepressants work by pausing the reuptake process so that the neurotransmitter can remain in the gap between your brain cells for a longer amount of time, thereby increasing the amount of time that these neurotransmitters can lead to activity in the next brain cell.


The most common reuptake inhibitors boost the activity of three types of neurotransmitters: serotonin, dopamine, and norepinephrine.


Serotonin: helps regulate mood, sleep, memory, emotional stability, sexual function and desire, and appetite.


Dopamine: involved in reward, motivation, memory, and pleasure. You may have heard of the “dopamine” rush you get when something great happens.


Norepinephrine: mobilizes the brain by boosting alertness, focus, and memory.


Increasing the brain activity for these three neurotransmitters can often boost your mood and/or improve your emotional stability.



How are antidepressants metabolized?


It’s important to know not only what antidepressants are meant to do to your brain, but also to understand how your body reacts to the introduction of these antidepressants.


Your body metabolizes, or breaks down, medication via enzymes. There are actually just six enzymes that are responsible for metabolizing more than 90% of all psychiatric medications. These six enzymes belong to a family of 60 genes that are found mostly in the liver.


Most people have genetic variants that can influence their response to medication. For example, one person may be an “ultra-rapid metabolizer” for one type of antidepressant–and therefore metabolize the antidepressant too quickly to provide any symptom relief–and simultaneously be a “poor” metabolizer for a different type of medication. 


So, now we know what antidepressants are and how they interact with your brain and body. But, there are dozens of types of antidepressants out there. How do we know which one might be best for you?



How do antidepressants differ from each other?


Reuptake inhibitors are traditionally sorted into three families. They have acronyms that you might have heard of: SSRIs, SNRIs, and NDRIs. 


There are many other types of antidepressants, but these are the main families that have generic brand names that you might be familiar with. For example, Zoloft, Prozac, and Wellbutrin and their respective generic names (sertraline, fluoxetine, and bupropion) are well-known antidepressants.






Full name

Selective serotonin reuptake inhibitor

Serotonin-norepinephrine reuptake inhibitor

Norepinephrine-dopamine reuptake inhibitor

Chemicals affected


Serotonin, norepinephrine

Dopamine, norepinephrine

Brand examples

Prozac, Zoloft, Celexa

Pristiq, Cymbalta


Generic names

Fluoxetine, escitalopram, citalopram, sertraline

Duloxetine, desvenlafaxine



Each of these families and each of the individual antidepressants within these families have nuanced differences that affect how they might impact your body. Your doctor will prescribe you a certain antidepressant or combination of antidepressants with the goal of tailoring them to your medical history and displayed symptoms. 


For example, Wellbutrin (bupropion), an NDRI, may interact negatively with an asthma medication you might be already taking, and so it might be better to take Prozac, an SSRI, instead. On the contrary, you might want to avoid Prozac if you are taking medication for migraines or seizures. As always, your doctor will know the best type of antidepressant, dosage, and treatment plan for you.



The bottom line


Antidepressants are proven to help most people for whom they are prescribed, but there’s no guarantee they will work for everyone. Working with a psychiatrist gives you a great chance of finding an appropriate medication, since they specialize in mental health treatment and are familiar with many more medications than other providers like primary care providers. 


Even when working with an expert psychiatrist, there is some amount of trial and error when selecting what treatment will be best for you. One way to reduce the guesswork for your doctor is to take a pharmacogenetic test. That’s because 90% of people have a DNA variant that could influence their treatment. 


As mentioned previously, these genetic variants can impact how fast your body metabolizes a certain medication, which in turn can impact the effectiveness of the medication. You want to avoid choosing an antidepressant that might produce unwanted side effects or negligible results. Many providers offer genetic testing to their patients because they are proven to reduce the risk of side effects and increase your chance of getting better.

Wondering if you are especially likely to benefit from pharmacogenetic testing? You can take a few minutes to take this free pharmacogenomics quiz that will tell you whether or not a DNA test might help you in your mental health journey. You can also take a look at the following articles if you’d like to learn more about medications for your mental health. Happy reading!