Anxiety can cause a wide range of emotional, physical and psychological symptoms that can dominate a person’s entire life. One way to treat this condition is with antidepressants. Whilst many GPs will prescribe this medication on a short-term basis, some patients favour long-term use of antidepressants for their anxiety.

In this article, we’ll explain what antidepressants are and how they work. We’ll also explore why people might choose to take antidepressants indefinitely and how this can affect their physical and mental wellbeing.

Table of contents

• What are antidepressants?
• How do antidepressants work?
• Types of antidepressants used to treat anxiety
  • Selective serotonin reuptake inhibitors (SSRIs)
  • Serotonin and noradrenaline reuptake inhibitors (SNRIs)
  • Noradrenaline and specific serotonergic antidepressants (NASSAs)
  • Monoamine oxidase inhibitors (MAOIs)
• How long can you take antidepressants?
  • Fear of relapse
  • Uncomfortable withdrawal process
  • Experiencing relapse
• Long-term effects of taking antidepressants
• How to manage long-term antidepressant use
  • Keep a record
  • Schedule regular visits to your GP
  • Only stop medication with your GP's guidance
  • Combine antidepressants and therapy
• The bottom line

What are antidepressants?

Antidepressants are a type of medication that is commonly used to treat clinical depression and a variety of other conditions, including:

• Anxiety disorder
• Bulimia
• Childhood bedwetting
• Fibromyalgia
• Neuropathy
• Obsessive-compulsive disorder (OCD)
• Panic disorder
• Phobias
• Post-traumatic stress disorder (PTSD)
• Premenstrual syndrome (PMS)

As some of these conditions are chronic, many people will have to take antidepressants for most of their life to prevent symptoms from returning.

How do antidepressants work?

It’s believed that antidepressants work by boosting the levels of certain neurotransmitters in the brain or making them last longer. This includes brain chemicals like serotonin, dopamine and noradrenaline, which regulate your emotion and mood.

By altering your brain chemistry, antidepressants can improve your mood and reduce anxiety symptoms. They can also help to reduce certain pain signals activated by nerves, which is why they are used to treat chronic pain conditions.

While antidepressants may be effective in treating certain anxiety symptoms, they won’t help you address the cause of your condition. This is why medication is often used in combination with certain psychotherapies like cognitive behavioural therapy (CBT).

Types of antidepressants used to treat anxiety

There are many different types of antidepressants available for people with anxiety. Though they affect brain chemicals in similar ways, they can cause different side effects. As such, some people will respond better to one type of antidepressant than another.

Below, we’ll highlight the main types of antidepressants for anxiety and explain how they work, their side effects and how long they’re usually prescribed for.

Selective serotonin reuptake inhibitors (SSRIs)

Selective serotonin reuptake inhibitors (SSRIs) are the most widely prescribed type of antidepressant. They are usually the first choice over other antidepressants as they tend to cause fewer side effects.

SSRIs work by helping the brain use its serotonin levels more effectively. They block a process called reuptake which involves nerve cells reabsorbing serotonin—increasing the amount of time that it is active for. This, in turn, will serve to improve your mood and increase feelings of happiness.

The most common types of SSRIs include:

• Sertraline (Lustral)
• Escitalopram (Cipralex)
• Paroxetine (Seroxat)

It will usually take around 2 to 6 weeks for SSRIs to start reducing anxiety symptoms. If an SSRI is effective, patients will usually take it for another 6 to 12 months before gradually decreasing the dose.

Serotonin and noradrenaline reuptake inhibitors (SNRIs)

Serotonin and noradrenaline reuptake inhibitors (SNRIs) were developed to be a more effective alternative to SSRIs. This is because they take a two-pronged approach in blocking the reuptake of both serotonin and noradrenaline.

Interestingly, however, there is no evidence to suggest this is the case. Indeed, SSRIs and SNRIs appear to be equally effective. As such, if treatment with SSRIs doesn’t work, your GP will recommend an SNRI.

The most common types of SNRIs include:

• Venlafaxine (Effexor)
• Duloxetine (Cymbalta and Yentreve)

Much like SSRIs, if treatment proves effective after an initial few weeks, you will take your SNRI for approximately 6 to 12 months before slowly reducing your dosage and finishing treatment altogether.

Noradrenaline and specific serotonergic antidepressants (NASSAs)

If SSRIs or SNRIs are ineffective, your GP may recommend a lesser-prescribed type of antidepressant: noradrenaline and specific serotonergic antidepressants (NASSAs).

NASSAs affect the same neurotransmitters as SNRIs, except that the process is slightly different. While SNRIs block the reuptake of serotonin and noradrenaline to make them last longer, NASSAs increase the number of these neurotransmitters.

The most common NASSA prescribed in the UK is Mirtazapine (Zispin).

It can take approximately 4 to 6 weeks for a NASSA to take full effect, though it will usually cause sedation immediately. Your GP will likely recommend taking medication for at least 6 to 12 months before eventually tapering off.

Monoamine oxidase inhibitors (MAOIs)

Monoamine oxidase inhibitors (MAOIs) are an older type of antidepressant that is used to treat certain depression and anxiety disorders. They are rarely prescribed anymore due to the development of more effective antidepressants that have fewer severe side effects.

MAOIs work by reducing the activity of an enzyme called monoamine oxidase (MAO). This enzyme breaks down the neurotransmitters that regulate your mood, including dopamine, noradrenaline and serotonin. Having less MAO means that you have higher levels of these neurotransmitters and improvements in mood.

The most common types of MAOIs include:

• Tranylcypromine (Parnate)
• Phenelzine (Nardil)
• Isocarboxazid (Marplan)

MAOIs will usually start to become effective within 2 to 3 weeks. GPs will typically recommend that patients take the antidepressant for at least 6 months for maximal benefit.

How long can you take antidepressants?

The duration of your treatment will vary depending on how severe your anxiety is, what types of side effects you may be experiencing and how comfortable you are taking the medication.

As we’ve explored in our section on types of antidepressants, GPs will usually recommend patients take antidepressants for an initial 2 to 6 weeks to determine their effectiveness before continuing for an additional 6 to 12 months.

Once this time has passed, GPs will begin a tapering period, in which your dosage is slowly lowered over weeks or months, depending on how long you’ve taken the medication. This is to reduce potential withdrawal symptoms, which we’ll explore further below.

Of course, some people will take antidepressants for a much longer time. For example, the NHS states that those with recurrent depression may be advised to take them indefinitely. Certain individuals may even choose to continue for the following reasons:

Fear of relapse

After suffering from anxiety for an extended period of time, it can feel like you’re finally in control of your life once you’re on an antidepressant. The thought of losing this peace of mind, however, is frightening enough to keep some people taking their medication indefinitely—even when there’s no evidence to suggest that a relapse would occur.

Uncomfortable withdrawal process

Discontinuing your antidepressants can lead to an uncomfortable withdrawal process. During treatment, your body gradually adjusts to a new level of neurotransmitters, so if the levels suddenly plummet, it can lead to some unpleasant symptoms.

According to the NHS, these symptoms can include:

• Restlessness
• Trouble sleeping
• Unsteadiness
• Sweating
• Stomach problems
• Feeling as if there’s an electric shock in your head
• Feeling irritable, anxious or confused

Some people will only experience these symptoms for 1 to 2 weeks, while others will deal with them for several months. Though a tapering period will reduce the severity of these symptoms, they can still be uncomfortable enough to push people to continue their long-term use of antidepressants.

Furthermore, the appearance of symptoms like anxiety can convince patients that they’re having a relapse—making them believe that they need to go back on their medication.

Experiencing relapse

Some people manage to push through the withdrawal process, usually due to a long tapering period, only to end up experiencing debilitating anxiety symptoms that put them back at square one. In cases like this, long-term use of antidepressants can feel like the best option for their physical and mental wellbeing.

Long-term effects of taking antidepressants

Figures published by NHSBSA showed that the number of people prescribed antidepressants reached approximately 8.32 million in 2021/2022. In spite of this, we’re still only just beginning to grasp what their long-term effects might be.

A 2016 study by Cartwright et al. looked into the experiences of long-term antidepressant use over the course of 3 to 15 years. The majority of patients were happy with the benefits of antidepressants. They did, however, report the following adverse effects:

• Withdrawal effects (73.5%)
• Sexual problems (71.8%)
• Weight gain (65.3%)
• Feeling emotionally numb (64.5%)
• Addicted (43%)

Many patients were specifically concerned about the severe withdrawal symptoms that “undermined their confidence to discontinue should they wish to and therefore limited their choices”.

Long-term antidepressant treatment can cause a host of health risks, such as “high rates of sexual dysfunction, bleeding (in particular gastrointestinal), weight gain, risk of fracture and osteoporosis, and hyponatremia.” Research by the University of Bristol also found that long-term antidepressant use was associated with an increased risk of heart disease.

How to manage long-term antidepressant use

If you’re taking antidepressants indefinitely to treat your anxiety, there are a few steps you can take to manage or prevent any potential adverse long-term effects.

Keep a record

The best way to determine whether or not an antidepressant is working is to record your mood, emotions, potential symptoms and side effects. Your GP will use this information to dictate future treatment recommendations.

For example, if you notice that your antidepressant is causing severe side effects that have not subsided within a few weeks, your GP may recommend switching to an alternative antidepressant.

As an example of what you should be keeping an eye out for, check out this antidepressant monitoring form.

Schedule regular visits to your GP

You’ll need to sit down with your GP regularly, at least twice a year, to determine whether:

• You still need to be on antidepressants
• Your medication is working effectively
• They need to modify the dosage or switch antidepressants

Your GP will want to know how you’re adjusting to your medication, so you’ll want to bring your record with you. Don’t be afraid to ask them questions if you’re concerned about a certain side effect—they’ll be able to offer reassurance or an alternative treatment option.

Only stop medication with your GP’s guidance

Even if you’re convinced that your medication is causing various negative side effects, you must talk to your doctor before you stop taking your antidepressant.

The dosage of your antidepressant will need to be gradually reduced, usually over a period of 4 weeks, but it can be much longer if you’ve been taking it for months or years.

This is to minimise and prevent withdrawal symptoms from occurring when you come off antidepressants suddenly—and to make it easier to reverse course if your anxiety makes a resurgence.

Combine antidepressants and therapy

To reduce the chances of relapse should you choose to discontinue your antidepressants, you should consider trying a combination of medication and psychotherapy.

A 2015 study reports that combined treatment can help to reduce relapse even at two years. A meta-analysis conducted by Harvard Medical School also found that people who undergo psychotherapy while tapering off an antidepressant are less likely to relapse.

Indeed, psychotherapy, like cognitive behavioural therapy (CBT), can teach you valuable coping skills like the Anxiety Equation to help you manage your anxiety symptoms effectively and minimise your chances of relapsing.

The bottom line

Though research is still ongoing into the effects of long-term use of antidepressants, one thing is clear: there are some real health risks and withdrawal effects that need to be carefully considered by patients.

Taking antidepressants is a big decision, as is the choice to continue taking treatment for the long term or stopping altogether. To ensure that patients are doing what’s best for their physical and mental wellbeing, it’s crucial that they remain well-informed every step of the way by their GPs.