What Is The Difference Between An SSRI And An SNRI?
- For those experiencing suicidal thoughts, please contact the 988 Suicide & Crisis Lifeline at 988
- For those experiencing abuse, please contact the Domestic Violence Hotline at 1-800-799-SAFE (7233)
- For those experiencing substance use, please contact SAMHSA National Helpline at 1-800-662-4357
Note: The information found in this article is not a substitute for professional medical advice. Seek the advice of your physician or other qualified health providers with any questions you may have. In addition, consult a medical doctor before starting, changing, or stopping any medication or medical treatment.
Understanding your medications and their intended use may help you and your healthcare provider determine their effectiveness. Various mental health conditions and physical illnesses can be treated with medications. However, side effects and efficacy can differ for everyone. If you have been diagnosed with a mental health condition and your healthcare provider advises that you take antidepressant medication to manage symptoms, it can be valuable to be well-informed about the medicine.
Overview: Neurotransmitters and depressive disorders
While the exact cause of depressive disorders is unknown, studies have suggested that disturbances in serotonin, dopamine, and norepinephrine messaging in the central nervous system may lead to the development of a depressive disorder. Both serotonin and dopamine are neurotransmitters, chemical messengers that control core functions in the human body, including mood and emotions. Below are a few ways these chemicals and neurotransmitters interact with the brain and body.
Dopamine
Dopamine is integral to the brain's reward system and influences learning, movement, mood, and sleep. It is also a precursor to the release of norepinephrine and epinephrine.
Serotonin
Serotonin is a neurotransmitter, a chemical that transmits messages between nerve cells in the brain. It can also be found in the other parts of the central nervous system, smooth muscles of the cardiovascular and bronchial systems, and small amounts in the digestive system.
Serotonin plays a significant role in controlling emotions, mood, and it is implicated in aggression, depressive conditions, and anxiety disorders. If your serotonin levels are low or high, you may experience physical and psychological symptoms. For example, serotonin is derived from tryptophan, an amino acid present in foods. If your diet is low in tryptophan, it may lead to serotonin deficiency, which can cause a depressed mood or anxiety.
Norepinephrine
Like serotonin and dopamine, norepinephrine is a neurotransmitter that transmits nerve messages to elicit a response in the body. The interplay between these three neurotransmitters improves mood, builds resilience against stress, and increases energy. As dopamine and serotonin work to control emotions and improve cognitive functions, epinephrine – a hormone released during the fight-or-flight response – causes a boost of energy along with clarity of thought and attentiveness.
What are SSRIs and SNRIs?
When considering neurotransmitters' roles in managing energy, concentration, mood, and overall cognition, one may begin to understand why they are a target when looking for a way to manage symptoms of depressive disorders. There are two main types of antidepressants that target serotonin and norepinephrine receptors, known as selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs). Although both classes are labeled as antidepressants, they can each be used to treat numerous mental health conditions, like depression, anxiety, post-traumatic stress disorder (PTSD), and obsessive-compulsive disorder (OCD).
SSRIs: Selective serotonin reuptake inhibitors
Serotonin levels can be boosted in several ways, including increasing the amount of serotonin available or decreasing the amount of serotonin lost through reuptake. The most common choice to improve serotonin levels is using an antidepressant called an SSRI. An SSRI works by increasing the level of serotonin available in the bloodstream by blocking the receptors that reabsorb it.
SSRIs can cause serotonin levels to rise to dangerous levels in the body, leading to a condition known as serotonin syndrome. While it may seem that excessive serotonin may put you in a better mood, serotonin syndrome can potentially be life-threatening. Serotonin syndrome can be caused by the therapeutic use of serotonergic substances, like SSRIs and other serotonergic medications, related to an overdose, or result from an interaction between multiple similar medications.
If your serotonin levels get too high, you may notice symptoms like the following:
- Shivering
- Diarrhea
- Confusion
- Headaches
- Twitches
- Heart palpitations
- Seizures
- High blood pressure
- Muscle spasms
A blood test may not detect serotonin syndrome. If you experience any of the above symptoms and have recently started taking an SSRI or had your SSRI dosage increased, speak with your doctor immediately. If left untreated, serotonin syndrome can be fatal.
SNRIs: Serotonin and norepinephrine reuptake inhibitors
Serotonin and norepinephrine reuptake inhibitors (SNRIs) work slightly differently than SSRIs. Though both medications increase the amount of serotonin available in the bloodstream, SNRIs block the reabsorption of serotonin and norepinephrine. While SSRIs are mainly used only for mental health conditions, SNRIs can also be used for other conditions (like to relieve pain), and they are more effective for certain people. SNRIs may be less likely to cause rapid mood cycling in people with bipolar disorder. They are more often prescribed only for short-term use for depression in those with bipolar disorder due to the risk of hypomania or mania after use.
These medications are not only used to treat depression, anxiety, and other mental health disorders, but they also are effective in treating fibromyalgia and nerve pain due to their effect on norepinephrine levels, which has a natural analgesic (pain killing) effect. SNRIs were created in the 1990s and are newer than SSRIs, which are from the 1980s. Providers usually recommend that SNRIs are not taken with SSRIs because of the risk of serotonin syndrome.
Like SSRIs, SNRIs can cause serotonin syndrome by raising serotonin levels to dangerously high levels. Other symptoms, like anxiety, sweating, and restlessness, are more likely with SNRIs for select people. In addition, SNRIs may cause liver problems if used long-term. With both SSRIs and SNRIs, there are risks of suicidal thoughts and behaviors, especially in children and adolescents.
If you are experiencing suicidal thoughts or urges, call the 988 Suicide & Crisis Lifeline at 988 or text 988 to talk to a crisis provider over SMS. They are available 24/7 to offer support. 988 also offers an online chat for those with an internet connection.
Both types of medications have serious withdrawal symptoms. Consult your doctor before making any changes. Withdrawal signs can include anxiety, upset stomach and diarrhea, tiredness, and muscle aches. Alcohol can worsen withdrawal symptoms and increase the risk of serotonin syndrome. Neither can be prescribed to pregnant and nursing women.
SSRIs and SNRIs: Is one better than the other?
Serotonin is responsible for various bodily functions, including emotional control, sleep cycling, and cognitive functions. When treating depression, physicians may consider using an SSRI or SNRI. While these medications are most often prescribed for depression, they have other uses too.
SSRIs target serotonin levels alone, so are usually used only to treat depression and anxiety. An upset stomach is a common symptom of anxiety and depression and may be related to low serotonin levels. This relationship is known as the "brain-gut connection," as the neurological system that lines the gastrointestinal tract is also known to utilize serotonin. For this reason, SSRIs may also be used to treat gastrointestinal stress.
SNRIs inhibit the absorption of norepinephrine, a neurotransmitter known to inhibit pain when levels are increased. Norepinephrine is released during a fight-or-flight response and stimulates the adrenal system. The stimulus of this hormone can raise the heart rate and blood pressure, increase energy, cause the blood to thin, and increase attentiveness.
These medication effects make SNRIs an option for treating not only depressive disorders but also pain disorders like fibromyalgia and low blood pressure. Evidence also shows SNRIs may reduce symptoms of migraines and other pain-related symptoms. Still, SNRIs are more rarely used for these conditions due to better or more effective medications available.
Are SNRIs or SSRIs more effective?
According to research, certain SNRIs showed better results compared to all other SSRI medications given to clients with severe depression. SNRIs may be more expensive than SSRIs. However, the cost can vary, based on insurance, location, and year.
Some doctors combine antidepressants for treatment-resistant depression. One potential challenge with SSRIs and SNRI medications is that, while they are often considered to be highly effective, their effectiveness can decrease over time. For this reason, doctors may have clients switch medications after prolonged use of a single antidepressant. Talk to your doctor if you notice worsening symptoms.
SNRIs’ additional effect on norepinephrine levels means that SNRIs improve energy levels in addition to one's overall mood. While SNRIs may appear to be a more effective choice overall, each person is unique, and what works for one may not work for another. Some people may find significant improvement with SSRIs. Your doctor can work with you to find a medication that meets your unique needs.
Other support options
Because medications are often offered temporarily, therapy can be used alongside treatment for more long-term care. A therapist can help you develop coping mechanisms unique to your condition and talk about how your symptoms impact your life. They may also offer worksheets, external resources, and activities to practice.
If you are facing any challenges that keep you from seeking therapeutic support in your area, you might also consider online counseling through a platform like BetterHelp, which may be more convenient. Online platforms allow you to be matched with a practitioner based on your preferences. Although they do not offer medication management or prescription, you can learn various therapeutic modalities and techniques with your therapist from home. In addition, you can pick between phone, video, or chat sessions.
One study found that online therapy's Working Alliance Index score was higher than in-person therapy in several areas. The composite score for online therapy was 215.07, compared to 205.5 for face-to-face therapy. Study participants primarily sought therapy for depression, anxiety, and relationship challenges. They cited written communication, cost, and flexibility as factors contributing to their overall positive experience with online therapy compared to in-person options.
Takeaway
Frequently asked questions
Read more below for answers to questions commonly asked about this topic.
Why use an SNRI instead of an SSRI?
The choice between using serotonin-norepinephrine reuptake inhibitors (SNRIs) or selective serotonin reuptake inhibitors (SSRIs) in the treatment of depression or other mood disorders depends on various factors, including the individual's specific symptoms, medical history, and how they respond to the medication. Both SNRIs and SSRIs are types of antidepressant medications, but they work in slightly different ways and may be more appropriate for different individuals. Below are reasons a healthcare provider might choose an SNRI over an SSRI:
- Different neurotransmitter systems: Certain neurotransmitters may impact an individual in different ways. SNRIs affect both serotonin and norepinephrine levels in the brain, whereas SSRIs primarily target serotonin. Some individuals may not respond well to SSRIs alone, and they may benefit from the dual action of SNRIs, particularly if their depression also involves symptoms like fatigue, low energy, and low motivation, which are associated with a chemical imbalance called norepinephrine deficiency.
- Anxiety symptoms: SNRIs may be preferred when a person with depression also experiences significant anxiety symptoms. Norepinephrine has a role in the body's stress response, and medications that increase norepinephrine levels may help manage anxiety symptoms in addition to depressive symptoms.
- Treatment-resistant depression: In cases where individuals do not respond adequately to SSRIs, healthcare providers may try SNRIs as an alternative. If an SSRI is ineffective, switching to an SNRI can be considered to see if the different mechanism of action leads to a better response.
- Pain management: SNRIs can also be used to manage chronic pain conditions, like neuropathic pain or fibromyalgia. This can be a good option for individuals who have both depression and chronic pain.
- Individual response: People's responses to medications can vary widely. Some individuals may respond better to one class of antidepressants over the other due to their unique brain chemistry and genetic factors. Finding the most effective medication for a specific person often requires trial and error.
- Side effects: SSRIs tend to have different side effects than SNRIs. An individual's tolerance for and experience of side effects can influence the choice of medication. For example, SNRIs are more likely to cause increased heart rate, blood pressure, and sweating compared to SSRIs, which may be a consideration for some patients.
The decision to use an SNRI or an SSRI should be made in consultation with a healthcare provider who can assess the individual's specific needs and monitor their progress to determine the most suitable treatment.
Are SNRIs better than SSRIs for anxiety?
Whether SNRIs (serotonin-norepinephrine reuptake inhibitors) are better than SSRIs (selective serotonin reuptake inhibitors) to treat anxiety depends on the individual and the specific anxiety disorder being treated. Both classes of antidepressants can be effective in managing anxiety, but their mechanisms of action and potential side effects differ, which may make one more suitable than the other in certain situations. Consider the following when discussing a medication with your provider:
- Type of Anxiety Disorder: The choice between SNRIs and SSRIs can depend on the specific anxiety disorder being treated. For example, generalized anxiety disorder (GAD) often responds well to both SNRIs and SSRIs. However, social anxiety disorder and panic disorder may respond better to SSRIs in some cases.
- Symptom Profile: The type and severity of anxiety symptoms one experiences can influence the choice of medication. SNRIs, with their norepinephrine activity, may be recommended when anxiety symptoms are accompanied by low energy, fatigue, and low motivation, as norepinephrine plays a role in arousal and energy levels.
- Co-Existing Conditions: If anxiety is occurring alongside conditions like depression or chronic pain, an SNRI may be a preferred choice, as it can address both mood and pain symptoms.
- Individual Response: Response to medication varies from person to person. What works best for one individual may not work as well for another. Some individuals may respond better to an SNRI, while others may do better with an SSRI. Finding the most effective medication for a specific person may require trial and error.
- Side Effects: SNRIs and SSRIs can have different side effect profiles. SNRIs are more likely to cause side effects that pertain to their norepinephrine activity, such as increased heart rate, blood pressure, and sweating. On the other hand, SSRIs are generally associated with side effects like sexual dysfunction and gastrointestinal symptoms. The choice of medication may depend on an individual's tolerance for specific side effects.
- Drug Interactions: Considerations related to medication interactions, especially if the individual is taking other medications, can influence the choice between SNRIs and SSRIs.
- Personal Preference: In some cases, a person's preference for a particular medication based on their prior experience or concerns about side effects can be a valid factor in choosing between SNRIs and SSRIs.
What is the difference between antidepressant SSRI and SNRI?
Antidepressant medications known as SSRIs (selective serotonin reuptake inhibitors) and SNRIs (serotonin-norepinephrine reuptake inhibitors) are both commonly used to treat depression and certain other mental health conditions. While they have some similarities, they also have key differences in terms of their mechanisms of action and the neurotransmitters they primarily affect. Below is a breakdown of the differences between SSRIs and SNRIs:
SSRIs (Selective Serotonin Reuptake Inhibitors):
- Mechanism of Action: SSRIs primarily target the neurotransmitter serotonin. They work by blocking the reuptake (reabsorption) of serotonin in the brain, increasing its availability in the synaptic cleft (the gap between nerve cells). This process is believed to control mood.
- Neurotransmitter Affected: Serotonin is the primary neurotransmitter affected by SSRIs. Serotonin controls sleep, appetite, and other emotional and behavioral functions.
- Indications: SSRIs are commonly used to treat depression, generalized anxiety disorder (GAD), obsessive-compulsive disorder (OCD), panic disorder, social anxiety disorder, post-traumatic stress disorder, and various other mood and anxiety disorders.
- Side Effects: Common side effects of SSRIs can include sexual dysfunction, gastrointestinal symptoms (like nausea or diarrhea), and, in some cases, an increased risk of weight gain.
SNRIs (Serotonin-Norepinephrine Reuptake Inhibitors):
- Mechanism of Action: SNRIs target serotonin and norepinephrine simultaneously. They work by inhibiting the reuptake of both of these neurotransmitters. This dual action can have a different impact on mood and overall arousal compared to SSRIs.
- Neurotransmitters Affected: SNRIs primarily affect serotonin and norepinephrine. Norepinephrine is associated with alertness, energy, and the "fight or flight" response.
- Indications: SNRIs are used to treat conditions like major depressive disorder, generalized anxiety disorder, fibromyalgia, chronic pain conditions, and certain anxiety disorders. They are often considered when individuals experience symptoms like low energy, fatigue, or pain in addition to depression or anxiety.
- Side Effects: While SNRIs can cause side effects similar to those of SSRIs, such as sexual dysfunction and gastrointestinal issues, SNRIs may be more likely to cause side effects related to norepinephrine, such as increased heart rate, blood pressure, and sweating.
What is the number one prescribed antidepressant?
Pinpointing a single "number one prescribed antidepressant" can be challenging because prescribing patterns can vary by region, healthcare provider, and individual patient needs. Talk to your doctor to find the right medication for you.
What are the pros and cons of SNRIs?
SNRIs (serotonin-norepinephrine reuptake inhibitors) are a class of antidepressant medications commonly prescribed for various mood disorders and certain pain conditions. Like most any medication, SNRIs have their pros and cons, and their suitability depends on individual factors and medical considerations. Below are some of the potential pros and cons of SNRIs:
Pros of SNRIs:
- Broad Action: SNRIs target both serotonin and norepinephrine reuptake, which may be beneficial for individuals with depression or anxiety symptoms that involve both neurotransmitters. This dual action can provide a more comprehensive approach to managing mood and emotional control.
- Effective for Some Pain Conditions: SNRIs like duloxetine can be effective in managing certain chronic pain conditions, such as neuropathic pain, fibromyalgia, and musculoskeletal pain.
- Potential for Improved Energy and Alertness: Norepinephrine is associated with alertness, energy, and motivation. SNRIs may be helpful for individuals who experience symptoms of low energy, fatigue, or lack of motivation as part of their depression.
- Fewer Sexual Side Effects: Some individuals experience fewer sexual side effects with SNRIs compared to some other classes of antidepressants like SSRIs. However, this result can vary among individuals.
- Individual Response: Different people respond differently to antidepressant medications. SNRIs may be more effective for some individuals who do not respond well to other classes of antidepressants.
Cons of SNRIs:
- Side Effects: SNRIs can cause side effects for some individuals, which can include nausea, dry mouth, dizziness, increased heart rate, increased blood pressure, and sweating. These side effects can be bothersome and may lead to discontinuation of treatment in some cases.
- Discontinuation Syndrome: Like SSRIs, SNRIs can lead to discontinuation syndrome when stopped abruptly. Stopping a medication abruptly can cause symptoms like dizziness, nausea, headache, and irritability. Tapering off the medication under a healthcare provider's guidance is usually recommended.
- Interactions with Other Medications: SNRIs can interact with other medications. Tell your healthcare providers all medications you are taking to avoid potential complications.
- Not Suitable for Everyone: SNRIs may not be suitable for individuals with certain medical conditions or a history of certain mental health disorders. A healthcare provider should consider the patient's medical history, potential contraindications, and risk of medication and supplement interactions.
- Cost: Some SNRIs can be more expensive than other classes of antidepressants, and the cost may vary depending on insurance coverage.
- Individual Variation: What works well for one person may not work as effectively for another. Finding the right antidepressant often involves a trial-and-error process.
- Pregnancy and Breastfeeding: SNRIs may have potential risks during pregnancy and breastfeeding, and the decision to use them should be carefully considered with a healthcare provider.
Can you switch from SNRIs to SSRIs?
It may be possible to switch from an SNRI (serotonin-norepinephrine reuptake inhibitor) to an SSRI (selective serotonin reuptake inhibitor) under the guidance of a healthcare provider. Reasons for switching between these two classes of antidepressants may be indicated to manage side effects, improve effectiveness, or address specific symptoms. When considering an antidepressant, discuss the impact of an SSRI vs SNRI with your doctor.
Why are SSRIs the best?
SSRIs (selective serotonin reuptake inhibitors) are a class of antidepressant medications that have been widely prescribed and studied for the treatment of depression and various other mental health conditions for many decades. While SSRIs are effective for many individuals, no SSRI is universally the "best" antidepressant, as the choice of medication depends on individual factors. Additionally, some people find support solely from other treatment methods without using medication.
What is the most effective SNRI?
The effectiveness of SNRIs (serotonin-norepinephrine reuptake inhibitors) can vary from person to person, and there is no single SNRI that is universally considered to be the "most effective" for everyone. The choice of an SNRI depends on individual factors, including the specific condition being treated, the severity of symptoms, the presence of co-occurring conditions, and individual responses to the medication.
Are SNRIs more expensive than SSRIs?
The cost of antidepressant medications, whether they are SSRIs (selective serotonin reuptake inhibitors) or SNRIs (serotonin-norepinephrine reuptake inhibitors), varies widely based on several factors, including the specific medication, dosage, location, insurance coverage, and whether generic versions are available. Consider the following factors that may play a role:
- Generic vs. Brand-Name: Generic versions of SSRIs and SNRIs are often available, and they tend to be less expensive than brand-name versions. Generic medications contain the same active ingredients and are often equivalent in terms of safety and effectiveness. Healthcare providers and insurance companies may encourage the use of generics when appropriate to reduce costs.
- Insurance Coverage: The cost of antidepressant medications is often significantly influenced by your health insurance coverage. Different insurance plans have different formularies, which list the medications they cover and the associated copayments or co-insurance costs. Some plans may cover certain SSRIs or SNRIs with lower out-of-pocket costs than others.
- Dosage: The dosage prescribed by your healthcare provider can affect the overall cost. Higher dosages may require more frequent refills and, consequently, higher medication costs.
- Pharmacy Discounts and Coupons: Some pharmacies offer discounts and coupons that reduce the costs of antidepressant medications. Additionally, some pharmaceutical companies offer patient assistance programs to help individuals afford their medications.
- Manufacturer and Specific Medication: The cost of antidepressant medications can vary by manufacturer and specific medication. Some newer or less commonly prescribed SSRIs and SNRIs may be more expensive than older, more established medications.
- Location: Medication prices can vary by location and pharmacy. Different pharmacies may have different pricing structures, so it may be worthwhile to compare prices at multiple locations.
- Availability: The availability of generic versions and competing brands can affect the cost. Competition in the market can sometimes lead to lower prices.
Which SSRI works the fastest?
Among the SSRIs (selective serotonin reuptake inhibitors), the onset of action and the speed at which they begin to alleviate symptoms of depression or anxiety varies between people. However, some SSRIs are considered to have a relatively faster onset of action compared to others. Individual responses to these medications can differ, so what works fastest for one person may not be the same for another. Talk to your doctor about which medication may be beneficial for you.
- Next Article