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When it comes to healing mental health, some people doubt the effectiveness of medications. Others, like my doctor and I, know they’re essential for relieving some people’s symptoms from mental illnesses like generalized anxiety disorder and depression. As with many health treatments out there, some medications will work better for others and some may not work at all.

If you or someone you know has experience with anxiety or depression—whether seasonal, situational, or chronic—you may have wondered about the effectiveness of taking medication. Does it actually work? Are there any alternatives? Here’s what you need to know about how medication works to ease anxiety and depression.

Note: for the purposes of this article, I will only discuss how medication affects unipolar disorders (like depression) as treatment differs for bipolar disorders (like manic depression).

The two main types of meds: SSRIs and SRNIs

There are two main classes of antidepressants that may be used to treat a major depressive disorder or generalized anxiety disorder: Selective Serotonin Reuptake Inhibitors (SSRIs) and Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs). SSRIs and SNRIs work differently, but in general, both affect chemical messengers (neurotransmitters such as serotonin and norepinephrine) in the brain. Our brain cells use neurotransmitters to communicate messages between each other via nerve endings. SSRI and SNRI medications change brain chemistry to help the right brain cells better regulate the body’s responses to mood changes, stress, tension, sleep, and even pain associated with mental illness.

Serotonin, the happy hormone

Medical News Today reports that the neurotransmitter serotonin “is sometimes called the happy chemical, because it contributes to wellbeing and happiness.” The article adds that serotonin “is believed to help regulate mood and social behavior, appetite and digestion, sleep, memory, and sexual desire and function.” Studies have found that one of the immediate benefits of exercise is an increase in a positive mood. Research published by the Scandinavian Journal of Medicine & Science in Sports in 2013 states that a “reduction in blood serotonin after exercise is similar to the effects of selective serotonin reuptake inhibitors.”

Fascinating fact: some diets and nutrition supplements claim to increase serotonin levels. Your gut produces serotonin, and certain foods may help increase this type of production. But according to an article published by the Federation of European Biochemical Societies, research has established that this serotonin can’t cross the blood-brain barrier. This means any serotonin your brain uses must be produced inside your brain. While eating more of a certain nutrient or food may increase serotonin in the gastrointestinal tract, it can’t cross over into the brain’s chemical processes.


Like serotonin, norepinephrine is a neurotransmitter in the brain. Research published by ScienceDirect explains that norepinephrine is related to drive, motivation, and the “fight or flight” response. ScienceDirect reports that low levels of norepinephrine are associated with increased fear and antisocial behavior.

How antidepressants work in the brain

SSRIs and SNRIs work similarly to ease anxiety and depression by increasing levels of serotonin, norepinephrine, or both, in the brain. Remember that serotonin and norepinephrine are neurotransmitters, or chemical messengers, that transmit signals between brain cells. Sometimes, brain cells reabsorb these chemical messengers too quickly, which means there are less of them available. SSRIs and SNRIs work to slow down the reabsorption (i.e., the reuptake) of serotonin or norepinephrine in the brain, making more of them available for chemical messaging work.

If you’re still confused, don’t worry. I wasn’t quite clear on it either, even after years of taking both types of medications. Author and illustrator Katie Mckissick of Beatrice the Biologist drew this brilliant graphic that gives a much friendlier explanation of how SSRIs and SNRIs “work” between brain cells.

Depression and anxiety can feel like an impenetrable mystery when you or someone you love is in the midst of them. And it’s hard to grasp how something as concrete as a pill could affect something as ethereal as our emotions. For me getting a better grasp of what my medications are doing has helped me understand why it’s not always mind over matter.

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