Depression is a widespread condition in the UK, reflecting prescribing trends for antidepressant drugs. In recent years antidepressants have become the fastest-growing class of drugs in the UK. In 2019, four million more antidepressant items were prescribed as compared to 2018, reaching 74.4 mln prescribed items.
In this post, I will be looking at the most common antidepressants in the UK. I will also discuss the rationale behind the popularity of some commonly used antidepressants in the UK.
Antidepressant Prescribing In The UK Statistics
74.4mln antidepressant items were prescribed in 2019. This number has been rising at an average rate of 3.5mln items per year since 2015 (data period covered in this post), although it is known that this value has been on the rise for over 25 years (Mars, et al, 2017).
Most Common Antidepressants In The UK By Class
Selective Serotonin Re-Uptake Inhibitors (SSRIs) are the most used antidepressant class in the UK (54.09%). SSRIs are followed with ‘other’ antidepressants, mainly Serotonin and Norepinephrine Reuptake Inhibitors (SNRIs), with 23.09% of all antidepressants prescribed, and Tricyclic & Related Antidepressants are third with 22.78%.
As a class, Monoamine-Oxidase Inhibitors (MOI) came fourth with 0.05% of total antidepressants prescribed in the UK.
The popularity of SSRIs reflects the guidelines in the management of Depression in the UK. NICE guidelines recommend antidepressant treatment for people with moderate to severe Depression. The first episode of Depression is managed with one of the following SSRIs:
- Paroxetine or
SSRIs are preferred antidepressants as there are less toxic in overdose and are better tolerated than other classes of antidepressants.
Some antidepressants such as Amitriptyline and Duloxetine can be used to treat neuropathic pain, which limits available prescribing information as this prescribing data is not solely available.
NICE recommends both Amitriptyline and Duloxetine as first-line treatments in the management of neuropathic pain.
10 Most Common Antidepressants In The UK
Items prescribed for each antidepressant taken for the year 2019.
Items prescribed: 16.7 mln
Sertraline is the most common antidepressant in the UK. Sertraline belongs to the SSRI group of antidepressants, which are recommended as the first-line in the treatment of Depression.
Although NICE guidelines do not recommend a specific SSRI as the first line, Sertraline is recommended when a patient has a chronic physical health problem due to a lower risk of interactions with other drugs. Sertraline is also recommended as a first-line SSRI for people who have unstable angina (chest pains) or who had a recent heart attack. Some studies have found Sertraline can treat premature ejaculation.
Since 2015 the number of items prescribed for Sertraline doubled, showing the biggest growth out of all antidepressants in the UK.
Sertraline is recommended for the management of generalized anxiety disorder (unlicensed use) and panic disorder (NICE, 2015) in addition to the management of Depression, post-traumatic stress disorder, and social anxiety disorder, making it more popular than the second most popular SSRI on the list, Citalopram. Sertraline made it to the top 15 most popular drugs in the UK.
Items prescribed: 14.0 mln
Citalopram is the second most common antidepressant, which also belongs to the SSRIs class of antidepressants. Since 2015 no significant changes in prescribing have been seen for Citalopram.
As explained in the above paragraph, Citalopram is recommended only in the management of depression and panic disorders. Citalopram is the 15th most popular drug in the UK.
Items prescribed: 13.9 mln
Amitriptyline is the most prescribed tricyclic antidepressant. Although tricyclic antidepressants are similarly effective to SSRIs, they are not recommended as first-line treatment in Depression due to several associated side effects, which may cause discontinuation of the treatment by a patient.
Tricyclic antidepressants are more sedative therefore some patients may benefit if they experience sleeping problems alongside Depression.
Amitriptyline is also recommended as one of the first-line drugs in the management of neuropathic pain (NICE, 2019), which partly explains the place in the top 3 most popular antidepressants in the UK (Read: Amitriptyline for nerve pain). Sole information for the management of Depression is not available for this drug, limiting analysis for this post.
Items prescribed: 9.6 mln
Mirtazapine is considered the second line in the management of Depression, usually when a patient fails to respond to the initial treatment with an SSRI (NICE, 2019).
There is some evidence suggesting Mirtazapine offers a clinically relevant treatment option for the acute phase of major Depression as compared with other antidepressants by having a faster onset of action than other SSRIs (Watanabe et al, 2011).
Some patients have been prescribed Mirtazapine in addition to SSRI or SNRI, although there is no evidence to show the benefits of this combination treatment (BMJ, 2018).
Items prescribed: 6.8 mln
Fluoxetine is the third most popular SSRI on the list. No significant changes are observed in the use of Fluoxetine. Fluoxetine can be used to manage menopausal symptoms, such as hot flushes, and the management of Depression.
Fluoxetine can affect how other drugs are metabolized (changed into the active form) in the liver, which explains why this drug is not a favorable SSRI in the management of Depression.
Items prescribed: 4.6 mln
Although classified as ‘other’ antidepressant, Venlafaxine belongs to a group of antidepressants called Serotonin and Norepinephrine Reuptake Inhibitors (SNRIs). Venlafaxine is considered in the treatment of a more severe form of Depression (NICE, 2019).
Items prescribed: 2.6 mln
Duloxetine is another SNRIs on the list. A significant increase in prescribing can be seen for Duloxetine. Since 2015 prescription items for this drug have almost doubled. Until 2013, Duloxetine was only available only as a branded drug called Cymbalta.
Patent expiration for Cymbalta and significant cost reduction for prescribing drive the increase in popularity of this drug. Duloxetine is the only antidepressant on the list, which is also used to manage diabetic neuropathy and moderate to severe stress urinary incontinence.
Items prescribed: 1.3 mln
Paroxetine popularity is slightly on the decrease (Items prescribed in 2015: 1.4mln versus 1.3 mln in 2019). Similar to Fluoxetine, Paroxetine can interact with many drugs, through the mechanism explained earlier, which affects the popularity of this antidepressant.
Items prescribed: 1.2 mln
Although prescribing volume for Escitalopram is low as compared to other SSRIs, the general trend for Escitalopram prescribing is on the rise, with the highest number of prescriptions for this drug recorded in 2019.
Escitalopram is related to Citalopram. They both have the same chemical formula. However, the arrangement of atoms in ‘space’ is different.
There is little evidence to suggest Escitalopram is more effective than Citalopram in the treatment of Depression (Read: Escitalopram vs Citalopram). Additionally, Escitalopram is much more expensive than Citalopram, explaining the much lower popularity of the drug.
Items prescribed: 1.2 mln
With 1.2ml prescription items last year, Trazodone is closing the top 10 most common antidepressants in the UK. Trazodone is reserved for patients who did not respond to the first-line antidepressant and when sedation is required.
Why Are Monoamine Oxidase Inhibitors (MOI) Not Popular Antidepressants?
MOI became obsolete drugs in the management of Depression. This class of antidepressants is not used very often because of a number of interactions with common foods such as alcohol, meat products, fish, and milk products.
Conclusion: Why An Increasing Number of Antidepressants Are Prescribed?
The complexity of antidepressant prescribing and in-depth analysis across the UK population is beyond the scope of this post. At an individual level, a number of factors can cause Depression, some of which include stressful life events, personality, family history of Depression, giving birth, alcohol, and drug use (NHS, 2016).
Some previously suggested trends contributing to the rise of antidepressant prescribing include an increase in long-term use of antidepressants rather than new cases of patients being diagnosed (Mars, et al, 2017). Some studies found an increase in antidepressant prescribing after the 2008 recession, specifically in younger men, due to rising unemployment (Kendrick et al., 2015).