Depression: How effective are antidepressants?

Photo of a man taking some medicine (PantherMedia / Diego Cervo)

Like psychological approaches, antidepressants are a key part of treating depression. They aim to relieve symptoms and prevent depression from coming back.

Opinions vary on how effective antidepressants are in relieving the symptoms of depression. Some people doubt they help, while others consider them to be essential. But as is true for many other treatments, these medications may help in some situations, and not in others. They are effective for moderate, severe and chronic depression, but probably not for mild cases. They can also have side effects. It is important to discuss the pros and cons of antidepressants with your doctor.

The main aim of treatment with antidepressants is to relieve the symptoms of depression, such as feeling very sad and exhausted, and prevent them from coming back. The medications are designed to restore emotional balance and help people to get on with everyday life. They are also taken to relieve symptoms such as restlessness, anxiety, sleep problems and suicidal thoughts.

This information deals with using medication to treat the most common form of depression, namely unipolar depression. The treatment of manic depression (bipolar disorder) is not discussed here.

What antidepressants are available?

Many different drugs are available for the treatment of depression. They can be split up into different groups. This article mainly provides information about the following, most commonly used antidepressants:

  • Tricyclic antidepressants (TCAs)
  • Selective serotonin reuptake inhibitors (SSRIs)
  • Selective serotonin noradrenaline reuptake inhibitors (SSNRIs)

Tricyclic antidepressants have been on the market the longest. They are considered to be first generation antidepressants. SSRIs and SSNRIs are second generation antidepressants.

The following are prescribed less often:

  • Alpha-2 blockers
  • Monoamine oxidase (MAO) inhibitors
  • Selective noradrenaline reuptake inhibitors
  • Selective noradrenaline/dopamine reuptake inhibitors
  • Melatonin receptor agonists and serotonin 5-HT2C receptor antagonists

There are also medications like trazodone and lithium that don't belong to any group, as well as herbal products such as St. John's wort.

How do antidepressants work?

The nerve cells in our brain use various chemicals to pass on impulses. Even though not all details are known, experts believe that depression is caused by an imbalance of certain chemicals like serotonin which then affects some nerve connections. Antidepressants aim to increase the availability of these chemicals. The various drugs do that in different ways.

What does the treatment involve?

Antidepressants are usually taken daily. The goal in the first few weeks and months is to relieve the symptoms and, if possible, make the depression go away. Once that has been achieved, the treatment is continued for at least four to nine months. This continuation therapy is necessary to stop the symptoms from coming back. The medication is sometimes taken for longer to prevent relapses. The duration of treatment also depends on how the symptoms develop over time and whether there is an increased risk of relapse. Some people take antidepressants for several years.

Regular appointments with the doctor are important during treatment. There you can talk about whether the symptoms have improved and whether there are any side effects. The dose will be adjusted if necessary. By no means should you increase or reduce the dose on your own. If you do, the tablets might not work properly or they may cause more side effects.

Towards the end of the treatment, the dose is gradually reduced over the course of several weeks. You may experience temporary sleep problems, nausea or restlessness while coming off the medication. These problems are especially common if you stop taking antidepressants suddenly. Sometimes people stop taking their medication as soon as they start feeling better. But doing so increases the likelihood of the depression returning. Unlike many sleeping pills and sedatives, though, antidepressants do not cause physical dependence.

How effectively do antidepressants relieve symptoms?

There are a lot of different medications for depression. But it's difficult to predict how well a particular medication will help an individual. Because of this, doctors often first suggest taking a drug that they consider to be effective and relatively well tolerated. If it doesn't help as much as expected, it's possible to switch to a different medication. Sometimes a number of different drugs have to be tried out before you find one that works.

Studies show that the benefit generally depends on the severity of the depression: The more severe the depression, the greater the benefits are likely tobe. In other words, antidepressants are effective against chronic, moderate and severe depression. They probably don't work in the treatment ofmild depression.

The various antidepressants have been compared in many studies. Overall, the commonly used tricyclic antidepressants SSRIs and SSNRIs performed equally well. Studies of adults with moderate or severe depression showed:

  • Without antidepressants: About 20 to 40 out of 100 people who took a placebo noticed an improvement in their symptoms within six to eight weeks.
  • With antidepressants: About 40 to 60 out of 100 people who took an antidepressant noticed an improvement in their symptoms within six to eight weeks.

In other words, antidepressants improved symptoms in about 20 more people out of 100.

 

Illustration: How well antidepressants can relieve symptoms - as described in the article

 

Antidepressants can also relieve long-term depression (chronic depressive disorder (dysthymia) or chronic depression) and help make itgo away completely.

An antidepressant can already have an effect within one or two weeks. But it may take longer for the symptoms to improve.

Additional medication can also be taken. That might help to relieve the symptoms, but no antidepressant can guarantee that. It can take a long time for a medication to start helping some people. Other people still have symptoms even after trying several different medications. They can then discuss the alternative treatment options with their doctor.

How effectively do antidepressants prevent relapses?

Antidepressants are usually taken for one to two years, sometimes longer, to prevent relapses. Relapse prevention may be a good idea for people who

  • have already had several relapses,
  • absolutely want to avoid a relapse, or
  • have chronic depression.

Studies involving adults show that taking commonly used antidepressants such as TCAs, SSRIs or SSNRIs lowers the risk of relapses, but cannot completely prevent them.

  • Without preventive treatment: About 50 out of 100 people who took a placebo had a relapse within one to two years.
  • With preventive treatment: About 23 out of 100 people who took an antidepressant had a relapse within one to two years.

In other words, taking an antidepressant for a longer period successfully prevented a relapse in an average of 27 out of 100 people.

 

Illustration: How effectively antidepressants can prevent a relapse - as described in the article

What side effects do antidepressants have?

Like all medications, antidepressants can have side effects. Over half of all people who useantidepressants report experiencing side effects. They usually occur during the first few weeks of treatment and are less common later on.

Some of these side effects are believed to be a direct consequence of the medication's effect on the brain and are relatively similar among various drugs of the same group. Patients who are taking antidepressants sometimes have a dry mouth, headaches, feel faint, anxious, and have a decreased sex drive. These kinds of symptoms are often perceived to be a side effect of the medications. But some of them may be caused by the depression itself.

Whether or not someone has side effects, which side effects they have, and how frequent they are will depend on the drug and on the dose used. And everyone reacts slightly differently to drugs as well. The risk of side effects increases if other medication is also being taken. One of the drugs may make the side effects of the other worse. These kinds of drug interactions are common in older people and people with chronic illnesses who are taking several different kinds of medication.

Because of this, it's important to discuss the pros and cons of the various medications with a doctor.

Some side effects are more common with particular drugs:

  • Compared to tricyclic antidepressants, SSRIs are more likely to cause diarrhea, headaches, sleep problems and nausea.
  • Tricyclic antidepressants are more likely than SSRIs to cause vision problems, constipation, dizziness, dry mouth, trembling and urination problems.

The side effects of tricyclic antidepressants are often worse than the side effects of SSRIs and SNRIs. As a result, more people tend to stop taking tricyclic antidepressants: Studies found that about 15 out of 100 people did so, compared with around 10 out of 100 people who were taking SSRIs. Taking an overdose of tricyclic antidepressants is also more likely to lead to severe side effects than taking an overdose of the other antidepressants.

Severe side effects

Antidepressants can make you feel dizzy and unsteady on your feet, increasing the risk of falls and broken bones, especially in older people. Interactions with other medications can increase this risk.

A very small number of people have had heart problems, epileptic fits or liver damage while taking antidepressants. It is believed that these were rare side effects of antidepressants. Various studies suggest that teenagers consider suicide more often when taking SSRIs or SSNRIs and also actually attempt to take their own lives more often. Teenagers should see their doctor or therapist more regularly at the beginning of treatment so that any risk of suicide can be identified early on.

Things to consider when selecting an antidepressant

Whether antidepressants are an option depends on various factors, including the severity of the depression. Other aspects can also play a role:

  • Are you having psychological treatment or are you planning to?
  • Have you taken antidepressants before and did they help?
  • Would the possible benefits outweigh the potential side effects?

Potential side effects can also be key when choosing which drug to take: Some people might be more keen to avoid digestion problems. Others might prefer to avoid dizziness, decreased sex drive or erectile dysfunction.

For treatment with antidepressants to work, a careful diagnosis has to be made first. Experts believe that some people are prescribed antidepressants unnecessarily. The fact that significantly more people take antidepressants nowadays suggests that. These medications are sometimes already prescribed for milder cases, even though there is doubt about how well they work in mild depression.

On the other hand, it is important that severe depression is diagnosed and treated properly. Antidepressants can help here, and for some people may be the only way to cope in everyday life or enable them to start psychological treatment.

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Please note that we do not provide individual advice on matters of health. You can read about where to find help and support in Germany in our information “How can I find self-help groups and information centers?”

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