Starting antidepressants: Timeline of side effects and adjustment

You’ve just started taking an antidepressant, and you feel a little strange. Maybe you’ve also been experiencing side effects like nausea or insomnia.

You’re no doubt wondering if these feelings are normal, how long they’ll last, and whether you should talk to your doctor about changing your medication.

For most patients who have recently started on antidepressants, the side effects and the feeling that “something’s off” are normal. Stories from patients, as well as research on how antidepressants work, show that what you’re experiencing isn’t at all unusual. These effects often follow a predictable timeline and can start to ease after a few weeks or months.

“Antidepressants are associated with side effects most commonly during the first three weeks of taking the medication or at dose changes,” Shari Allen, PharmD, associate professor of pharmacy at the Philadelphia College of Osteopathic Medicine, said in an article from PsychCentral, a Healthline Media publication. “Most of the side effects, though, are transient, and they will often decrease with time and with continued use.”

Antidepressants growing in use

If you’re starting an antidepressant for the first time, you’re in good company: You’re one of the millions who have done so. According to 2015-2018 data from the U.S. Centers for Disease Control and Prevention, an estimated 13.2% of Americans had taken an antidepressant within the previous 30 days.

Younger people in particular have been taking antidepressants in greater numbers. From 2016 through 2022, antidepressant prescriptions for young adults and teens rose more than 66%, according to a study published by the American Academy of Pediatrics.

Side effects are among the most common fears patients express about starting antidepressants. It’s important to remember that side effects are often short-lived and that not everyone experiences them.

It’s also important to know that you might experience side effects before you see benefits from taking the medication. That’s because of how these medications work in the brain.

What to know about adjusting to antidepressants

Antidepressants work by changing brain chemistry. Brain activity may increase as quickly as five hours after the first dose, a 2016 study published in the journal Psychological Medicine found.

Research about brain chemistry began to uncover patterns as far back as the 1950s. In a 2009 article published in the journal Current Pharmaceutical Design, researchers discuss the discovery of MAOIs (monoamine-oxidase inhibitors) as a milestone in understanding the role of neurotransmitters – chemical messengers in the brain – in depression.

Today more is known about how antidepressants help patients. Benefits such as improvement in mood and increased energy typically take several weeks or more to kick in. As examples, here’s how long two of the most commonly prescribed antidepressants take to start working:

• SSRIs, or selective serotonin reuptake inhibitors, tend to start working within one to four weeks and require taking up to 12 weeks for the full benefit. They block serotonin, a type of neurotransmitter, from being reabsorbed by nerve terminals in the brain. The Cleveland Clinic says SSRIs tend to cause fewer side effects than other antidepressants because they have little effect on other neurotransmitters in the brain.
• SNRIs, or serotonin and norepinephrine reuptake inhibitors, typically take six to eight weeks for patients to feel beneficial effects. These help boost both serotonin and norepinephrine, a similar type of neurotransmitters. According to the Cleveland Clinic article on SNRIs, this class of antidepressant typically has mild side effects that improve over time.

What’s a typical timeline?

The initial phases of taking an antidepressant can frustrate patients by causing side effects while they see little or no improvement in their condition.

Mental health professionals say it’s important to understand how the medications work, be patient, and talk with your psychiatrist or primary care physician about your care. Your doctor can give you more information about what to expect and may consider changes in your treatment plan if your condition is not improving or if the side effects are severe.

Research shows that starting an antidepressant is one of the most important steps in a patient’s journey to improved mental health. It’s when patients and their doctors establish a closer relationship, discuss a treatment plan and address fears and misconceptions about using antidepressants, according to an article by Austrian researcher Siegfried Kasper, published in 2022 in the medical journal Advances in Therapy.

While each patient is different, a common timeline for adjusting to an antidepressant looks similar to the following:

Weeks 1-2: Initial Adjustment: During the first few weeks, you’re most likely to experience side effects as your body adjusts to the medication. In a list on the Mayo Clinic website, common side effects may include:

• Nausea
• Increased appetite and weight gain
• Fatigue and drowsiness
• Insomnia
• Dry mouth
• Constipation
• Dizziness
• Agitation, restlessness or anxiety
• Sexual side effects
• Heart-related effects

Weeks 3-4: Transition Phase: By weeks three and four, many of the initial physical side effects begin to subside as your body adjusts to the medication. Some people start noticing subtle improvements in mood, but full therapeutic effects are still developing. During this phase, you might experience:

• Gradual reduction in side effects
• Early improvements in sleep and anxiety
• Changes in energy level
• Mood fluctuations

Month 2 and Beyond: Stabilization Phase: This antidepressant adjustment period is when many patients realize more full benefits from the medication. You could see:

• Resolution of most side effects
• More consistent mood improvement
• Better sleep quality
• Improved concentration and energy
• Reduction in anxiety symptoms

How to cope with side effects when starting an antidepressant

If you experience side effects or unusual feelings after starting an antidepressant, you might find some relief in the following ways:

• Counseling: Cognitive behavioral therapy and other forms of talk therapy are often used in conjunction with medication. Research shows that results tend to be better and side effects less severe when talk therapy and antidepressants are combined, according to an analysis of studies published in the journal World Psychiatry.
• Symptom tracking: Recording your symptoms, which mental health professionals often suggest, can be effective in dealing with side effects. Many patients find mood-tracker apps to be effective.
• Managing specific symptoms: Modifying meal timing and food quantities, maintaining a consistent sleep pattern, staying hydrated, and other behavioral changes can help patients handle side effects such as nausea or insomnia.
• Support network: Family members and friends can be a source of strength and support when starting an antidepressant.

When to consider any changes in medication

Side effects when starting an antidepressant are typically normal and mild. Understanding what to expect and why you may be feeling a little different can help alleviate some of the concerns about taking antidepressants.

If side effects and strange feelings persist or are getting worse, schedule an appointment with your doctor. It’s critical to continue your medication until you and your doctor can discuss whether to make any changes in the antidepressant or dosage that you’re taking.

Getting better is a collaborative process. You and your doctor should work together to find the right antidepressant and other treatment choices that are right for you.

For more information about this topic and other topics, please visit:

https://genesight.com/blog/patient/5-things-to-know-before-starting-antidepressants/

https://genesight.com/blog/how-do-antidepressants-work/

https://genesight.com/blog/patient/how-to-minimize-antidepressant-side-effects/