Selective serotonin reuptake inhibitors (SSRIs) and selective serotonin and norepinephrine reuptake inhibitors (SNRIs) are two classes of medications that are commonly used to treat depression, anxiety, and other mental health disorders. 

These drugs are distributed via prescription. Although the science behind these medications is complex, they help the brain to restore normal levels of neurotransmitters like dopamine and serotonin. 

SSRIs are typically prescribed more often than SNRIs, but each of them has practical applications within the medical field. These are the most effective medications used in the treatment of depression. 

Common SSRIs include: 

• sertraline (Zoloft) 
• fluoxetine (Prozac) 
• escitalopram (Lexapro) 
• paroxetine (Paxil) 
• citalopram (Celexa) 
• fluvoxamine (Luvox) 

Common SNRIs include: 

• venlafaxine (Effexor) 
• duloxetine (Cymbalta) 
• levomilnacipran (Fetzima) 
• desvenlafaxine (Pristiq) 
• milnacipran (Savella) 

How Do These Medications Work? 

SSRIs and SNRIs work in similar ways. They have related side effects and take roughly the same amount of time to become effective as antidepressant treatment. It typically takes between six and eight weeks to feel the full effects of these medications. 

Both of them work by preventing the reuptake of specific neurotransmitters (serotonin and norepinephrine) in the brain, which helps regulate the amount of these neurotransmitters to normal levels. The reuptake of neurotransmitters refers to the process of them being absorbed back into nerve cells, which SSRIs and SNRIs slow down. Having too much or too little of these neurotransmitters can lead to depression. 

Serotonin controls brain functions such as mood, anger, appetite, sex drive, and memory, while norepinephrine impacts stress, attention and focus, and sleep. Regulating serotonin and norepinephrine leads to better sleep, more balanced moods, normal appetite levels, and better attention spans. 

There is still much to learn about how exactly SSRIs and SNRIs impact the brain, but the results tend to be very positive for most people who try these medications.  

Effectiveness Of SSRIs And SNRIs In Treating Depression Or Anxiety 

SSRIs and SNRIs can work for short or long-term treatment ranging from a few months to years. After about six months of treatment, the risk of a relapse into depression or anxiety symptoms lowers significantly. Both of these medications have similar efficacy rates. 

One study on antidepressants found that 23 out of 100 people had a depression relapse after stopping use compared to 50 out of 100 people who took a placebo antidepressant. The chances of a relapse are often lower when medication is prescribed alongside other treatments, such as cognitive behavioral therapy (CBT). 

In addition to helping with depression and anxiety disorders, SSRIs and SNRIs can also help with: 

• Obsessive-compulsive disorder (OCD)
• Eating disorders 
• Post-traumatic stress disorder (PTSD)
• Bipolar disorder 
• Fibromyalgia 
• Panic attacks 
• Certain forms of chronic pain 
• Seasonal affective disorder (SAD) 

Potential Side Effects Of SSRIs And SNRIs 

There are a few common side effects associated with SSRIs and SNRIs. These may include blurred vision, dry mouth, dizziness, tremors, insomnia, or nausea. The most often encountered side effect is sexual dysfunction, which may make it more challenging to become aroused or achieve orgasm. 

Fortunately, many people find that these side effects lessen or go away completely after a few weeks. If you have any concerns about side effects, discuss them with your healthcare provider as soon as possible. However, it’s important to continue taking any medications as directed to avoid mental or physical health problems. 

One potential risk of taking SSRIs is called serotonin syndrome, which is caused by a buildup of serotonin in the body. This can happen after starting a new medication or after an increase in dosage. It may also result from taking SSRIs with certain recreational drugs like MDMA.

Symptoms of serotonin syndrome include:

• confusion
• dilated pupils
• headaches
• fevers or chills
• nausea and vomiting
• increased heart rate
• tremors or twitches
• sweating

If you experience seizures, irregular heartbeat, fainting, or a high fever, contact 911 immediately. Although serotonin syndrome can be fatal, it is treatable if it is caught quickly.

While VeriNew does not prescribe these drugs yet, you can make an appointment with one of our doctors today to learn about the other mental health medications we have available.

Citations

1. Sansone, R. A., & Sansone, L. A. (2014). Serotonin norepinephrine reuptake inhibitors: a pharmacological comparison. Innovations in clinical neuroscience, 11(3-4), 37–42.
2. Sheffler ZM, Patel P, Abdijadid S. Antidepressants. [Updated 2023 May 26]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-.
3. Shelton R. C. (2019). Serotonin and Norepinephrine Reuptake Inhibitors. Handbook of experimental pharmacology, 250, 145–180.
4. Chu A, Wadhwa R. Selective Serotonin Reuptake Inhibitors. [Updated 2023 May 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-.
5. Clevenger, S. S., Malhotra, D., Dang, J., Vanle, B., & IsHak, W. W. (2018). The role of selective serotonin reuptake inhibitors in preventing relapse of major depressive disorder. Therapeutic advances in psychopharmacology, 8(1), 49–58.
6. InformedHealth.org [Internet]. Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG); 2006-. Depression: Learn More – How effective are antidepressants? [Updated 2020 Jun 18].
7. Webmd.com/brain/serotonin-syndrome-causes-symptoms-treatments