Antidepressants can help relieve the symptoms of depression. They can also help to treat social anxiety disorder, other anxiety disorders, and seasonal affective disorder.

They work by correcting chemical imbalances of neurotransmitters in the brain. Experts believe these are responsible for changes in mood and behavior.

This article will cover the different types of antidepressants, how they work, their side effects, other uses, and alternative options.

What is an important adverse effect to monitor for with all patients taking antidepressant medications?
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Doctors tend to divide antidepressants into different types. These include:

Selective serotonin reuptake inhibitors (SSRIs)

SSRIs are a first-line treatment option for depression.

Examples of SSRIs include:

Serotonin and norepinephrine reuptake inhibitors (SNRIs)

SNRIs are a newer class of antidepressant compared with SSRIs. However, they work in a similar way.

Doctors may prescribe SNRIs for:

Examples of SNRIs include:

  • duloxetine (Cymbalta)
  • venlafaxine (Effexor XR)
  • desvenlafaxine (Pristiq)

Tricyclic antidepressants (TCAs)

Doctors may recommend TCAs for depression, fibromyalgia, some types of anxiety, and chronic pain.

Examples include:

  • amitriptyline
  • amoxapine
  • clomipramine (Anafranil)
  • desipramine (Norpramin)
  • doxepin (Sinequan)
  • imipramine (Tofranil)
  • nortriptyline (Pamelor)
  • protriptyline (Vivactil)
  • trimipramine (Surmontil)

Monoamine oxidase inhibitors (MAOIs)

Due to their adverse side effects and drug-drug interactions, doctors do not typically suggest MAOIs as a first-line treatment option for depression. However, they may be an option if SSRIs do not work for depression.

Examples include:

  • phenelzine (Nardil)
  • tranylcypromine (Parnate)
  • isocarboxazid (Marplan)
  • selegiline (Emsam, Eldepryl)

Noradrenaline and specific serotoninergic antidepressants (NaSSAs)

Doctors use NaSSAs to treat anxiety disorders and depression.

Examples include mianserin (Tolvon) and mirtazapine (Remeron, Avanza, Zispin).

It is important to note that all drugs have side effects. Different antidepressants have different side effects. However, not everyone will experience them.

SSRIs and SNRIs

SSRIs and SNRIs can lead to:

SNRIs can also cause an increase in blood pressure. A person with a serious heart condition should not take the SNRI venlafaxine.

TCAs

TCAs may have the following side effects:

  • dry mouth
  • tremor
  • fast heartbeat
  • constipation
  • insomnia
  • weight gain

MAOIs

MAOIs can interact with other drugs. For example, if a person combined an MAOI with an SSRI, it could lead to serotonin syndrome. Serotonin syndrome is a serious condition in which a person has too much serotonin in their body.

MAOIs can also lead to:

MAOIs prevent the breakdown of tyramine. If a person consumes foods that contain tyramine, such as sausages, fish, and overripe fruit, it can lead to a hypertensive crisis. This is a severe increase in blood pressure that can lead to a stroke.

NaSSAs

These antidepressants can lead to side effects similar to SSRIs and SNRIs. They can also cause drowsiness and weight gain. However, they are less likely to cause sexual dysfunction, according to 2010 research.

Rarer side effects

Rarer side effects of antidepressants include:

  • Suicidal thoughts: Some studies have found that young adults and children may be at a higher risk of suicidal thoughts when they first start taking antidepressants. If side effects are very unpleasant, or if they include thinking about suicide, the person should speak with a doctor straight away.
  • Withdrawal symptoms: Some people who take SSRIs and SNRIs experience some withdrawal symptoms when they stop taking the medication. Withdrawal symptoms can last for 1–2 weeks, and can include:
    • anxiety
    • dizziness
    • nightmares or vivid dreams
    • electric shock-like sensations in the body
    • flu-like symptoms
    • abdominal pain

Antidepressants tend to be effective. However, everyone responds to medication differently.

According to the Institute for Quality and Efficiency in Health Care, 40–60% of people who took an SSRI or SNRI for depression noticed some symptom relief within 6–8 weeks.

The research notes that the more severe the depression, the greater the benefits of antidepressants may be.

There are many types of antidepressants. They all work differently and have different benefits, risks, and side effects.

A person should speak with a doctor about their individual circumstances. The doctor will help them find the best treatment option for them.

The Centers for Disease Control (CDC) note that there is a link between taking SSRIs during pregnancy and congenital abnormalities. However, this risk is very low.

For some people, the risks associated with stopping the medication are higher than those associated with continuing taking it.

If a person is pregnant and wishes to continue or begin taking antidepressants, they should speak with a doctor.

Tiny amounts of some antidepressants can enter breast milk. However, the CDC states that most will have no impact on milk supply or the child’s well-being.

People may wish to try the following:

Therapy

People with depression may wish to undergo therapy. Types of therapy that can help to treat depression include:

Learn more about available mental health resources.

St. John’s wort

Hypericum, made from the herb St. John’s wort, may help some people with depression. It is available over the counter as a supplement.

However, there are some possible risks associated with taking hypericum:

  • If combined with certain antidepressants, it can lead to a potentially life threatening increase in serotonin.
  • It can worsen symptoms of bipolar disorder and schizophrenia.
  • It might reduce the efficacy of some prescription medications, including antidepressants, birth control pills, some heart medications, warfarin, and some therapies for HIV and cancer.

It is important for a person to tell a doctor or pharmacist if they plan on taking St. John’s wort.

Light box

People who experience seasonal affective disorder may benefit from light therapy.

This involves sitting in front of a light box first thing in the morning for 30–45 minutes.

Diet and exercise

The CDC notes that regular physical activity can reduce a person’s risk of depression. People may wish to try three exercise sessions per week for 12–24 weeks.

Learn more about exercise as a treatment option for depression.

People may also benefit from eating a balanced, nutritious diet consisting of fresh and whole foods. They may wish to avoid refined and processed foods.

Learn more about foods to eat with depression.

While different antidepressants work in different ways, they all affect neurotransmitters. Neurotransmitters are chemicals brain cells use to communicate with each other.

According to a 2021 article, antidepressants work in the following ways:

  • SSRIs: These reduce the amount of serotonin the brain absorbs. This makes it easier for the brain cells to send and receive messages, leading to more stable moods.
  • SNRIs: These raise the levels of serotonin and norepinephrine in the brain. These neurotransmitters play a key role in stabilizing mood.
  • TCAs: These regulate the amount of serotonin and norepinephrine the brain absorbs. This helps to reduce feelings of anxiety and depression.
  • MAOIs: These target the brain enzyme monoamine oxidase, which helps to break down neurotransmitters such as serotonin. This can lead to more stabilized moods and less anxiety.

According to the United Kingdom’s National Health Service (NHS), people may begin to feel the benefits of the antidepressants after 1–2 weeks if the person has not missed a dose.

Some people may stop taking them because they believe the medications are not working. However, it is important to keep taking the medication exactly as their doctor has prescribed.

If a person has not felt any benefit after 4 weeks, they should speak with a doctor.

According to the NHS, doctors will typically suggest a person takes antidepressants for at least 6 months.

People should take their antidepressants exactly as their doctor has prescribed.

Antidepressants can help relieve symptoms of conditions such as depression and anxiety disorders. They work by correcting the balance of neurotransmitters in the brain.

Examples of antidepressants include SSRIs, SNRIs, TCAs, and NaSSAs. MAOIs may also be an option, though doctors prescribe these less often due to the risk of adverse side effects.

It can take several weeks for antidepressants to start working, and people may experience side effects.

Alternatives to antidepressants include therapy, diet and exercise, and St. John’s wort. However, depression is a serious condition that may need medical treatment. Anyone who experiences the symptoms of depression should speak with a doctor.