Six SSRI drugs and how they work

Medically reviewed by Julie Dodson
Updated March 18, 2024by BetterHelp Editorial Team
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If you are experiencing depression, anxiety, or some other mental health condition, you may have heard of SSRI drugs and asked yourself what they are and if they work. SRRI stands for selective serotonin reuptake inhibitor (SSRI), and these medications are often used to treat depression and other mental health conditions.

Below, we’ll discuss six primary SSRIs that have been approved by the FDA for the treatment of depression or other mental health conditions. Each one has different uses and may work differently for different people. 

How SSRIs work

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Many people believe that SSRIs work by helping you produce more serotonin, but this is a misconception. Instead, studies show that these medications work by keeping the brain from reabsorbing or reuptaking the serotonin already being produced. This may allow for a more significant build-up, and therefore, availability, of serotonin without affecting its actual production.

Serotonin is a neurotransmitter that is responsible for many functions in the brain, including emotion and mood. Studies have shown that people with clinical depression tend to have lower serotonin levels, which can contribute to depression. By allowing for a greater build-up of serotonin, SSRIs may help some people to experience relief from depression and anxiety.

Some SSRIs can be used for more than just depression. Certain SSRIs can be helpful in treating anxiety, post-traumatic stress disorder (PTSD), obsessive-compulsive disorder (OCD), insomnia, and other health conditions. 

Because SSRIs can help the brain retain a build-up of serotonin, they might take time to be effective. It may take two to four weeks before a patient notices a difference in mood or behavior. Therefore, for most patients, a continuous six- to eight-week treatment may be necessary before symptoms of depression are in remission.

It’s recommended that you take SSRIs as instructed and that you not miss doses. Most of these drugs have a half-life of about 20 hours. For a person to build up serotonin in the brain, the medication usually needs to be taken routinely. Otherwise, serotonin may begin to reuptake, and progress may be lost.

SSRIs and uses

There are six types of SSRI drugs, some with more than one brand name. The SSRI drugs are listed here by generic name, with the brand names listed in the description. The different SSRI drugs have different side effects and interactions. They are also sometimes prescribed for different conditions and situations other than depression. 

Citalopram

The brand name for citalopram is Celexa. Citalopram is one of the most commonly prescribed SSRIs for depression and anxiety. Side effects are generally mild but can occur occasionally. Citalopram is not approved for children or adolescents and has not been shown to be effective for that age group. Celexa is a once-per-day medication, usually taken in the morning or evening.

Uses

In addition to depression, citalopram has been used to treat anxiety disorders and other mental health conditions. It has been shown to help treat obsessive-compulsive disorder, premenstrual dysphoric syndrome, post-traumatic stress disorder (PTSD), and eating disorders. It can raise your energy levels and may give you a sense of well-being.

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Clinical studies

Many studies have been done on citalopram and its effectiveness in treating depression. One such study published in The American Journal of Psychiatry showed that after an eight-week treatment regimen, 27% of subjects experienced a remission of their depressive symptoms, according to results from the Hamilton Depression Rating Scale (HAM-D). 

Escitalopram

The brand name for escitalopram in the United States is Lexapro. Lexapro is one of the newer SSRIs used to treat depression. As with other SSRI drugs, the side effects of escitalopram are typically mild, although they can occur occasionally.

Uses

Escitalopram is typically only used to treat major depressive disorder for adults and adolescents aged 12 and older. It is also approved by the FDA for generalized anxiety disorder in adults. Little research has been done to show that it is effective for any other purpose. Therefore, unlike other SSRI drugs, escitalopram is not frequently prescribed for mental health conditions like eating disorders or obsessive-compulsive disorder.

Clinical studies

Many studies have been done to test the effectiveness of escitalopram in treating depression, especially when compared to other antidepressants and SSRI drugs. One such study published in Biological Psychiatry showed that escitalopram was “30-fold more potent” than citalopram for the treatment of depression. 

Fluoxetine

Fluoxetine is available in several brands. The most common brand name for fluoxetine is Prozac. The other brand names are Sarafem, Rapiflux, and Selfemra. Prozac has been used as an antidepressant and antianxiety medication for over three decades, although it is no longer as commonly used as some other SSRIs.

Uses

Prozac has been used to treat some mental health conditions beyond depression. For example, it has been used to treat panic disorder, bulimia nervosa, premenstrual dysphoric disorder, and obsessive-compulsive disorder. Prozac is the only SSRI approved by the FDA for children aged 8 and older.

Clinical studies

Many studies have been done over the years to test the effectiveness of fluoxetine on different mental health disorders. Most recently, studies have focused on the treatment of PTSD in veterans. One such study found that the symptomology of PTSD in veterans was significantly decreased after five weeks of treatment.

Fluvoxamine

The brand name for fluvoxamine is Luvox. This might not be as commonly used as other SSRI drugs. As with other SSRI drugs, the side effects tend to be mild. One effect that makes Luvox stand out from the other SSRIs is that it is sometimes used to help with insomnia.

Uses

Luvox has been used successfully as an antidepressant and antianxiety medication. However, its primary use is in the treatment of obsessive-compulsive disorder. It has also been shown to be effective with panic disorders and bulimia.

Clinical studies

Studies are still in process to determine the potential uses of fluvoxamine. One of the uses that has been studied involves fluvoxamine for insomnia. Research shows that fluvoxamine can increase the production of melatonin, a hormone in the brain that allows you to sleep. Therefore, it may be used to treat insomnia, but it can cause drowsiness. It’s recommended that you talk to a doctor about fluvoxamine and its side effects before taking it.

Paroxetine

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The commonly known brand name for paroxetine is Paxil. However, it is also marketed under the brand names Pexeva and Brisdelle. This SSRI may have more side effects than other SSRI drugs and is not as frequently prescribed as similar drugs.

Uses

Paroxetine is primarily used to treat depression and anxiety. It has also been used successfully in treatments of obsessive-compulsive disorder, panic disorders, PTSD, and severe forms of premenstrual syndrome. Studies are still in process to determine other potential uses for paroxetine.

Clinical studies

One distinction of paroxetine is that it has been proven to help with disorders unrelated to depression or anxiety. For example, one study found that paroxetine can successfully treat symptoms of diabetic neuropathy. Most patients given the drug had fewer symptoms of diabetic neuropathy, although the exact reason for this is still being investigated.

Sertraline

Sertraline, sometimes known by the brand name Zoloft, is commonly used as an antidepressant for major depressive disorder. This drug is different from many SSRIs because it has been shown to be effective for adolescents aged 12 or older.

Uses

In addition to treating depression, sertraline has been used to treat anxiety disorders like panic disorders and PTSD. It has also been used in the treatment of obsessive-compulsive disorder, premenstrual dysphoric disorder, and social anxiety.

Clinical studies

Studies have determined the effects of SSRI drugs on people under 18. One study found that Zoloft can be an effective short-term treatment for major depressive disorder in children and adolescents.

The above medications should only be taken as directed by a physician. The uses of each of these medications may evolve as research on SSRIs continues. 

Complementing SSRI treatment with therapy

If you experience depression, anxiety, obsessive-compulsive disorder, or another mental health condition, you don’t have to face it alone. A doctor may prescribe an SSRI or other evidence-based treatment for your symptoms. They may also recommend that you speak with a licensed therapist about what you’re experiencing.

A licensed therapist may be able to provide guidance and help you navigate the treatment process, whether you end up taking SSRIs or not. Studies have proven that online therapy can effectively treat anxiety, PTSD, depression, and OCD. Therapists typically treat individuals with these mental health conditions through (CBT). CBT typically aims to identify thought patterns causing negative outlooks and behaviors and then help individuals change those patterns. 

If you aren’t feeling well enough to visit a therapist’s office due to symptoms of depression, you might consider online therapy, which research shows to be just as effective as in-office therapy for depression and anxiety. With an online platform like BetterHelp, you can engage in therapy through video chat or just audio if that makes you more comfortable. Also, you can reach out to your therapist in between sessions via in-app messaging, and they’ll get back to you as soon as they can.

Takeaway

Selective serotonin reuptake inhibitors (SSRIs) have been used to treat several conditions, including depression, anxiety, PTSD, insomnia, and obsessive-compulsive disorder. Each medication can be used differently, and each individual can respond differently to each SSRI. 

If you’re experiencing symptoms of depression or some other mental health condition, you don’t have to face it alone. In addition to taking an SSRI prescribed by a physician, you may benefit from talk therapy, whether in person or online. With BetterHelp, you can be matched with a licensed therapist who has experience treating depression and anxiety. Take the first step toward relief from depression or other mental health conditions and reach out to BetterHelp today.

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