The popularity of antidepressants has changed significantly over time. The first antidepressants called MAOIs were discovered in the 1950s and instantly became the most popular class. As newer tricyclic antidepressants emerged just a few years later, many of them were preferred over MAOIs because they carried less side effects and food interactions. The goal with developing new drugs for depression has always been to improve upon past drugs in regards to efficacy, tolerability, and side effects.
In the late 1980s, the first SSRI medication Prozac hit the market (1987). It became very popular and a household name among antidepressants. By the year 1993, over 10 million people throughout the world had tried Prozac for their depression. Eventually this SSRI would become a household name in the antidepressant industry. Following Prozac, other drugs in the SSRI class emerged to the forefront as antidepressants.
Eventually researchers discovered that some people may respond better to drugs that influence both serotonin and norepinephrine. Originally called dual reuptake inhibitors, the goal of these drugs was to act similarly to SSRIs, except in addition to increasing serotonin, they would also increase norepinephrine. The first SNRI called Effexor was approved in 1993 and took the market by storm as an alternative to SSRIs.
Most Popular Antidepressants for 2015
Currently two out of the three most popular antidepressants of 2015 are new SNRIs. The rise in popularity for SNRIs is largely due to the fact that they can be utilized to treat conditions such as neuropathic pain in addition to depression. Another antidepressant that is considered “atypical” called Viibryd is newer and works slightly different than a standard SSRI. The current trend seems to involve creating medications that act similar to SSRIs with less side effects and ability to treat more conditions than just depression.
- Cymbalta (Duloxetine)
Cymbalta was first approved in 2004 to treat major depression as well as neuropathic pain. When it first emerged, it became very popular due to the fact that it was a new SNRI with different properties than previous SNRIs. The ratio of serotonin reuptake inhibition to norepinephrine reuptake inhibition was approximately 10:1 – different from other SNRIs on the market.
It is also commonly used for generalized anxiety disorder, fibromyalgia, as well as various types of musculoskeletal pain, especially in cases related to osteoarthritis. In some cases it is even prescribed off label to treat urinary incontinence (it is approved for this in the UK). As this drug gained approval to treat conditions other than depression, it quickly leaped to the top of antidepressants in regards to both sales and number of prescriptions. (Read: “Top selling psychiatric drugs of 2014” and “Most prescribed psychiatric drugs of 2014” for additional information).
The primary reason that this drug is the top antidepressant is related to the number of conditions that it can be used to treat. Additionally it has only been on the market for approximately 10 years, meaning it is still considered a very new antidepressant (others have been on the market for decades). Some studies, particularly one in a French medical journal called “Prescrire” found Cymbalta to carry significant side effects and be no more effective than other antidepressants.
Additionally many people who don’t find relief from the SSRI antidepressants typically end up trying SNRIs like Cymbalta. SNRIs are associated with less side effects and some people like them better because they address the possibility that low norepinephrine causes depression or can be as important as serotonin in certain cases. This molecule was first discovered in 1988, but initial trials were found ineffective. Drug company Eli Lilly would later make modifications to get this drug approved in 2004.
By 2012, Cymbalta sales had reached over $4 billion in the United States. In the past year from 2013 to 2014, this drug pulled in just shy of $3 billion with over 10 million monthly prescriptions. It is the top selling antidepressant and clearly the most popular in the United States as of 2014. Expect this drug to stay at the top of popular antidepressants for years to come.
- Pristiq (Desvenlafaxine)
Like Cymbalta, the new trend among popular antidepressants is that they work slightly different from standard SSRIs. Pristiq is another SNRI with inhibits reuptake of both serotonin and norepinephrine in the brain. This drug isn’t as unique as some of the others, but it is supposedly an improvement of the older SNRI called “Effexor.”
It contains a synthetic form of the primary active metabolite of the drug Effexor. Although Wyeth (the company responsible for Pristiq) claims that it is better than Effexor, this is up for debate. Many people actually prefer Effexor over this drug and it is noted as having different ratios of inhibition compared to Effexor. Pristiq inhibits serotonin to norepinephrine at a ratio of 10:1, compared to a 30:1 ratio for Effexor.
The inhibition ratio of this drug is equal to that of Cymbalta. The reason Pristiq has become highly popular is due to the fact that drug companies are encouraging doctors to switch their patients from Effexor to Pristiq. Since Effexor’s patent has expired, Pristiq was created to lure people into a new improved version of the drug, while making them pay top dollar.
It supposedly has less side effects and is “simpler” to take, but some argue that this is not the case. It only comes in dosages of 50 mg to 400 mg and none of the pills can be split (because this will affect the release). Since the lowest dose of the drug is 50 mg and it cannot be split (due to being controlled-release), some would argue that lack of ability to taper down to a lower dose can make Pristiq withdrawal symptoms very difficult to cope with.
In any regard, Pristiq was approved in 2007 and sales have been steadily rising. As an SNRI it will be touted as having less side effects than SSRIs and attempt to gain Effexor’s customer base. This drug is also being researched as a non-hormonal treatment option for menopause. Assuming it gets approval to treat menopause and possibly other conditions in the future, expect its popularity to stay high.
Sales for Pristiq were just over $600 million this past year, making it a distant second to Cymbalta. Over 3 million prescriptions were filled for Pristiq on a monthly basis throughout the past year (approximately one-third of Cymbalta). It is still a relatively new antidepressant to the market, so expect its prescription numbers and profits to continue climbing in upcoming years.
- Viibryd (Vilazodone)
Viibryd is another new antidepressant that was released in 2011 for the treatment of major depression. Although this drug affects serotonin, it functions slightly different from most SSRIs because it also acts as a partial antagonist of the 5-HT1A receptor. Many consider it to be categorized as an “atypical antidepressant.” Although the efficacy of this drug is no better than other antidepressants on the market, it may have a more favorable side effect profile.
Specifically, the side effect profile of Viibryd is considered favorable because there were no reports of significant weight gain or sexual dysfunction in clinical trials. The fact that it is not associated with weight gain or sexual dysfunction is a huge reason that many people are giving this drug a try. Additionally the selling points of: being a “new drug,” working different in respect to SSRIs, and having no significant “weight gain” or “sexual dysfunction” are giving people good reason to try this drug.
Additionally it is the newest among the three most popular antidepressants in 2014. It was reported that over 1.4 million prescriptions for Viibryd were filled on a monthly basis throughout the past year. Since it is a new drug with a favorable side effect profile, expect its popularity to stay high in upcoming years. Should it ever get approval to treat a condition in addition to major depression, it will remain near the top of the pack.
Other Popular Antidepressants
Listed below are more popular antidepressants. Although it is unknown as to whether the order of popularity is correct, this was their degree of popularity as of 2011. Celexa, Lexapro, Zoloft, and Prozac are thought to remain among the most popular SSRIs on the market, but other drugs like Trazodone have stayed competitive.
- Celexa (Citalopram): In the year 2011, Celexa had made a huge comeback taking the top of the charts with approximately 37.7 million prescriptions. As of 2009 it wasn’t even competing for the top spot and its spin-off drug Lexapro was outselling it. This drug was initially approved in 1998 and is approved to treat major depression. Its efficacy is considered average compared to other antidepressants as is its side effect profile.
- Zoloft (Sertraline): This is an SSRI antidepressant that was approved in 1991, and has been among the most successful antidepressants of all time. As of 2009, approximately 19.5 million prescriptions were filled, making it the second most popular SSRI. Many consider it to still be among the best SSRI medications developed. As of 2011 over 37 million prescriptions were filled for Zoloft, a considerably increase over prior years. It is approved to treat major depression, OCD, and anxiety disorders.
- Prozac (Fluoxetine): Roughly 19.49 million prescriptions for this drug were filled in 2009, 24.4 million in 2010, and the number increased to over 24.5 million prescriptions in 2011. Prozac was considered the very first SSRI medication to hit the market and was approved in 1987. It is widely regarded as the most popular antidepressant and some would consider “Prozac” to antidepressants as “Coke” is to soda. In addition to being approved for major depression, it is also used for OCD, eating disorders, and trichotillomania.
- Lexapro (Escitalopram): This drug remains among the most popular SSRIs and is considered among the most effective based on user reviews. It managed to fill about 27.7 million prescriptions in 2009 and back then it was considered the most popular antidepressant medication on the market. It is primarily utilized to treat major depression, but also is approved to treat generalized anxiety disorder. Many consider Lexapro to be a superior version of the drug Celexa due to the fact that it contains the clinically effective S-stereoisomer.
- Desyrel (Trazodone): This is an antidepressant that was invented in the 1960s, but didn’t receive FDA approval until 1981. It works as an SARI (serotonin antagonist and reuptake inhibitor) and is therefore different from most SSRIs. It has been approved for major depression, anxiety disorders, and in some cases insomnia. As of 2009, it was prescribed more than Cymbalta with nearly 19 million prescriptions. By 2011, the number of prescriptions had eclipsed 22.5 million.
- Paxil (Paroxetine): This drug initially hit the market in 1992 and it remains fairly popular. Paxil filled nearly 14 million prescriptions in 2011, and was one of the most popular SSRIs in its heyday. The drug received a lot of negative press in regards to discontinuation as well as being the only SSRI linked to causing birth defects. It has been approved for major depression in addition to OCD, anxiety disorders, PTSD, and to help manage hot flashes associated with menopause.
- Effexor XR (Venlafaxine): This was the first SNRI on the market in the United States and was first approved in 1993. It provided an alternative to SSRIs by targeting norepinephrine in addition to serotonin. As of 2009, roughly 15 million prescriptions were filled, and that number slightly dropped in 2011 to 12.5 million prescriptions of Effexor. Expect this medication to drop some more in upcoming years as the heavily marketed and newer Pristiq attempts to sway Effexor users to its brand. Effexor is approved to treat major depression, anxiety disorders, and phobias.
- Wellbutrin XL (Bupropion): This drug has remained one of the most popular atypical antidepressants due to the fact that it is associated with weight loss and no sexual side effects. In many cases it is utilized as an antidepressant augmentation strategy in combination with an SSRI. The drug was initially developed to help people quit smoking, and has been approved for smoking cessation in addition to major depression. In the form of “XL” extended release, roughly 12 million prescriptions were filled in 2011. The “SR” (sustained release) version of the drug was also prescribed 8.5 million times in 2011, making Wellbutrin one of the most popular antidepressants. It is classified as an NDRI (norepinephrine dopamine reuptake inhibitor), mostly affecting norepinephrine with negligible effects on dopamine.
New antidepressants to watch… 2015, 2016
There were a couple of new antidepressants that were approved less than one year ago in 2013. These antidepressants include: Brintellix and Fetzima, both of which act differently. Brintellix is classified as an atypical drug, while Fetzima is an SNRI that affects norepinephrine more than serotonin (making it unique compared to others SNRIs on the market).
Brintellix (Vortioxetine): This is an atypical antidepressant that hit the market in September 2013. It was created by Lundbeck, the same company that has marketed Lexapro and Abilify. Brintellix was recently approved to treat major depression in adults and the company is attempting to get it approved for generalized anxiety. It works as a SMS (serotonin modulator and stimulator) with a variety of other effects. As advertising campaigns begin to promote this drug, expect prescription numbers to skyrocket.
Fetzima (Levomilnacipran): This is an SNRI antidepressant that hit the market in July 2013. It was developed by Forest Laboratories, the same company that developed the new drug Viibryd. Fetzima has been approved to treat major depression and is considered a spin-off of the older drug Milnacipran, which is not approved in the United States. The unique aspect of this particular drug is that it inhibits norepinephrine reuptake to a greater extent than serotonin; all other SNRIs affect serotonin significantly more.
Why The Most Popular Antidepressants Change Over Time
There are several reasons why the most popular antidepressants change over time. Back in the 1990s and early 2000s, different antidepressants were popular than the ones today. Several reasons why the popularity of various drugs changes has to do with: better treatments being discovered, people wanting to try new drugs, marketing campaigns, and approval for alternative conditions.
- Better treatments (Efficacy): Some of the new antidepressants may work better for certain people compared to older drugs. Although no antidepressant has been found to be significantly “better” than the rest in terms of efficacy, some individuals find these new drugs to work very well. So for some people, they will inevitably be a more effective option than what was previously on the market.
- Favorable side effects (Tolerability): Some new drugs such as Viibryd are attempting to minimize side effects, specifically unwanted ones like weight gain and sexual dysfunction. When the side effect profile becomes more tolerable, more people will want to try the drug. This is part of the reason why so many people end up trying Viibryd.
- New drugs (Flashy): Let’s face reality… if you’ve tried a bunch of medications on the market and haven’t experienced relief from your depression, you’re probably waiting for the next big drug to get approval. So many people end up hoping that the next drug that comes out will be better than the rest – and usually this is not the case. Many times, people find that new drugs end up making them feel worse than older options. However, it’s the initial flash that can lure people into trying a new drug.
- Marketing campaigns: These days drug companies have become more innovative with their marketing. Especially for antidepressants like Cymbalta that have been approved to treat multiple conditions. Everywhere you look: TV, internet, doctors office, street corner, etc. there’s an advertisement for the drug. The heavy marketing is what gets many people to consider trying the drug.
- Approval for other conditions: When an antidepressant is approved to treat a condition other than depression such as anxiety, fibromyalgia, OCD, insomnia, or neuropathic pain, it instantly becomes more popular. Anything that is effective to treat a variety of conditions will get prescribed more frequently and become a household drug.
Back in 2005, Paxil was the most prescribed antidepressant followed by Lexapro. By 2010, Paxil wasn’t even among the top 25 psychiatric prescriptions, yet Lexapro remained a commonly prescribed medication. Additionally back in 2005 Cymbalta was relatively new to the market and although it was popular, it didn’t yet reach its peak in terms of number of prescriptions or sales.
Currently as of 2014, Cymbalta has worked its way up to becoming the most-prescribed antidepressant on the market. It has been largely successful due to the fact that it gained approval to treat a variety of conditions (in addition to depression) including: neuropathic pain, generalized anxiety, fibromyalgia, and various forms of chronic pain. The variety of uses for an antidepressant drug like Cymbalta have certainly contributed to its popularity.
Although Cymbalta is the top prescribed antidepressant of the past year, a couple of new drugs: Viibryd and Pristiq round out the top three most popular. In the top 100 most prescribed drugs throughout 2014 in the United States, only Cymbalta, Viibryd, and Pristiq made the cut. Two of these drugs are SNRIs, while the other is an atypical antidepressant.
What do these three drugs have in common? They are brand new and function differently than SSRIs. Cymbalta is an SNRI with a variety of uses, Viibryd hit markets in 2011 and is touted as having less side effects than standard SSRIs, while Pristiq is regarded an improved version of the older drug Effexor. In addition to the heavy marketing behind these drugs, approval to treat multiple conditions will continue to bolster popularity.
As for the next few years, we can expect similar trends to continue. As a new drug is released and gains approval for depression (and other conditions), it will become more popular. If it works even moderately well, has unique properties, with favorable side effects, it should climb the charts. Most psychiatric drugs can take about a decade to reach their full potential in sales and prescriptions.
Do not expect Fetzima and Brintellix to be the most popular drugs next year. But in the next few years, if trends continue, they will likely climb the popularity charts. People like new drugs, especially for depression where so many people are unsatisfied with the current market of medications. Expect trends to continue in future years until either the FDA finds a way to expedite its approval process and/or a company comes up with an innovative drug that is superior to the rest of the field.