Mirtazapine for Sleep: Uses, Side Effects & Alternative Insomnia Treatments

Dr. Colleen Ehrnstrom, PhD
Oct 31, 20215 min read
Girl standing at bright window in dark room

Sleep is becoming increasingly harder to come by. as the constant stress of the modern world has diminished both the quality and quantity of sleep. COVID-19 has only made things worse. Thus, people are turning to medications in the hope of a quick fix for their insomnia.

But traditional psychopharmacological treatment for insomnia (sleep medications) are a delicate balancing act because of addiction and tolerance issues. As a result, doctors prefer antidepressants with sedative properties to treat insomnia. Mirtazapine is one such antidepressant.

What is Mirtazapine?

Mirtazapine is approved to treat major depression, obsessive-compulsive disorder, and various anxiety disorders. Additionally, it is often prescribed 'off-label' for insomnia. Initially launched under the brand name Remeron, it is still sold as such even though other generic versions of the drug are available.

Mirtazapine works on the Central Nervous System (CNS) as an antidepressant. It increases the concentration of particular chemical messengers (called neurotransmitters) in the brain, such as noradrenaline and serotonin. These neurotransmitters are important contributors for an uplift in mood.

Does Mirtazapine Help With Sleep?

Increasing evidence suggests Mirtazapine is effective in treating depression-related insomnia. For instance, in a 2018 study, Mirtazapine was given to 28 male patients with depression, suicidal ideation, and insomnia symptoms. While six individuals dropped out due to side effects, twenty-two of them showed significant improvement or complete remission of both sleeplessness and suicidal ideation.

To understand how Mirtazapine helps with sleep, it is essential to grasp the effect of depression on sleep. Sleep is broadly divided into two phases- Rapid Eye Movement (REM) sleep and non-rapid eye-movement (NREM). We all need a certain amount of sleep time in both phases to feel fully rested. Depression is associated with adversely impacting these phases as studies show sleep cycles of people with depression have increased REM sleep density and decreased latency to enter REM sleep. In other words, affected patients spend more time in REM sleep and less in slow-wave sleep. This has a negative effect on overall sleep quality.

Mirtazapine mildly suppresses REM sleep. It also improves sleep continuity and duration due to its anti-histaminergic properties. Thus, the end result is deeper sleep.

However, the effects of Mirtazapine, much like other sleeping medications, are short-lived. This is because they function by keeping hyperarousal at bay. Unfortunately, the body adapts rapidly to the drug and its sedative effect, and after a few months, the effects are notably lowered (though some still benefit from what is known as placebo).

Mirtazapine Side Effects Related to Sleep

Mirtazapine use is associated with several side effects. These can range from weight gain, headaches, and dry mouth to feeling ill. In addition, Mirtazapine can also cause several sleep-specific side effects.

Sleep Disorders

Interestingly, some of the more prevalent side effects of Mirtazapine are sleep disorders such as Restless Leg Syndrome (RLS) and Periodic Limb Movements (PLM). In fact, studies show up to 30% and 67% of Mirtazapine users can experience RLS and PLM, respectively.

Further, insomnia is a well-known symptom of Mirtazapine discontinuation. Yes, you read that right! While Mirtazapine may help you sleep in the short term, changing the dose or discontinuing the medication can negatively affect your sleep. This is why it is important to consult your doctor before beginning, modifying, or discontinuing a medication. Starting, changing, or terminating a pharmaceutical regimen on your own can have serious consequences.

Daytime Drowsiness

Due to Mirtazapine's sedating properties, approximately 54% of users experience daytime drowsiness. This is particularly worrying for patients suffering from depression which itself causes sleepiness and exhaustion. Mirtazapine can make this situation worse.

Strange Dreams

Although rare, sudden Mitrazapine discontinuation can cause strange, vivid dreams and nightmares.

Ways To Treat Insomnia

People who have trouble sleeping frequently turn to medications first. Unfortunately, they are unaware of safer, more effective therapies. For instance, changing your sleeping habits can help you sleep better over time. Sleep habits support a reliable and predictable pattern for your mind and body.

You can prepare for a restful night of quality sleep by relaxing before bed. A warm bath or a relaxing massage are excellent options. It's also a good idea to make your surroundings conducive for sleep. Set your thermostat to the optimal temperature and remove all unnecessary distractions. You can even experiment with different sleeping positions to see what works best.

Furthermore, what you do during the day has a significant impact on how well you sleep. Although long naps can disrupt your sleep schedule, consider taking shorter naps or simply resting. Exercising during the day may also help you relax and sleep.

If you still have trouble sleeping, your doctor may prescribe cognitive behavioral therapy (CBT-I) for your insomnia.

Why CBT-I May Be The Best Cure For Insomnia

CBT-I is an evidence-based and clinically proven approach for treating sleep disorders.

Two forces govern sleep: Sleep drive and mental arousal (wake drive). These two drives operate independently but must work together for optimal sleep. Your sleep drive is typically strongest at bedtime. Your wake drive is your state of alertness. Understandably, it is easier to fall asleep when your sleep drive is high, and your wake drive is low.

CBT-I provides a comprehensive plan that strengthens your sleep drive and teaches you to calm your mind. It is highly effective, with research showing it helps up to 80 percent of participants achieve healthy and restorative sleep. Further, unlike sleeping pills and antidepressants which are only helpful for as long as you take them, the results are long-lasting.

Learn More

To learn more about how to effectively treat your insomnia and begin your journey to a medication-free restful night’s sleep, visit our website today.


Dr. Colleen Ehrnstrom, PhD

Dr. Colleen Ehrnstrom is a licensed clinical psychologist with a specialty practice in Acceptance and Commitment Therapy (ACT). Areas of expertise include insomnia and other sleep disorders, anxiety, and depression.

Dr Ehrnstrom is the co-author of the book End the Insomnia Struggle: A Step by Step Guide to Help you Get to Sleep and Stay Asleep which offers a comprehensive, personalized sleep program that integrates the physiology of sleep, cognitive behavioral therapy for insomnia (CBT-I) and acceptance and commitment therapy (ACT).

It’s time to stop blaming the night monsters.

Let’s work together to transform your sleep for the better.