Does Mirtazapine cause unusual dreams?

In this article, we will discuss Mirtazapine-induced unusual dreams or nightmares. We will talk about the incidence of this side effect and what research indicates about this side effect. We will also discuss what one should do if Mirtazapine causes unusual dreams. 

Does Mirtazapine cause unusual dreams?

Yes, Mirtazapine can cause unusual dreams or nightmares in some individuals. Some people have reported vivid or intense dreams that are often difficult to forget. Unusual dreams or nightmares are common with a number of antidepressants, and not just Mirtazapaine (1,2). 

However, it’s important to understand that everyone’s response to medication can vary, and not everyone will have these specific dream-related effects. If you do notice unusual dreams or nightmares while taking Mirtazapine, it’s essential to communicate this to your doctor.

What does research suggest?

Research studies have found a potential link between Mirtazapine and nightmares in people of different age groups. The exact incidence of this side effect is not well-established, but it is considered common with antidepressants generally. 

A 2006 case study included a 52-year-old man who experienced depressive symptoms like low mood, poor sleep, and more (3). He was prescribed Mirtazapine, but a day later, he began having vivid nightmares about being murdered, similar to a previous episode on Mirtazapine.

Researchers suggested that Mirtazapine’s effect on REM sleep might have induced these nightmares, as the drug is known to increase REM sleep, and other antidepressants that do the same, like Bupropion, have also been linked to vivid dreams and nightmares (3). 

Another case has been reported of Mirtazapine-induced nightmares and vivid dreams at a low dose in a young adult female, which lead to the discontinuation of treatment with this antidepressant (4).

Another recent research study focused on sleep disturbances in depressed patients and the effects of antidepressants, particularly Mirtazapine (5). It’s known that mirtazapine, due to its sedative properties, can improve sleep quickly, despite the controversy over its mechanisms. 

However, this research reports five cases of elderly patients (aged 69 to 79) with various conditions, where Mirtazapine led to intense nightmares, prompting treatment interruption (5). 

This indicates that Mirtazapine, in some cases, can cause nightmares so intensely that drug discontinuation becomes the only choice to improve the patient’s quality of life.

What to do if Mirtazapine causes unusual dreams?

If you’re experiencing unusual dreams or nightmares while taking Mirtazapine, it’s crucial to communicate this with your doctor. 

In some cases, if the dreams are tolerable and not causing significant distress, your doctor might suggest waiting it out, as this side effect might improve over time as your body adjusts to the medication. 

However, if the dreams become more severe or bothersome, your doctor might recommend adjusting the dosage. Your provider might decrease the dose, as sometimes a lower dose can alleviate this side effect. 

On the other hand, if the nightmares persist and are severely impacting your well-being, your doctor may consider discontinuing Mirtazapine and exploring alternative treatments. Mirtazapine stays in your system for about 4-9 days after the last dose, which means your body may take a week or two to recover. 

Remember, it’s not safe to stop using Mirtazapine without your doctor’s approval. 


In this article, we have discussed Mirtazapine-induced nightmares and how common they are. We have also discussed some published case studies which confirm that Mirtazapine may affect your sleep cycle or induce unusual dreams. We have also discussed what one should do if this side effect occurs.

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Jilani TN, Gibbons JR, Faizy RM, Saadabadi A. Mirtazapine. 2022 Sep 7. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan–. PMID: 30085601.


Tribl GG, Wetter TC, Schredl M. Dreaming under antidepressants: a systematic review on evidence in depressive patients and healthy volunteers. Sleep Med Rev. 2013 Apr;17(2):133-42. doi: 10.1016/j.smrv.2012.05.001. Epub 2012 Jul 15. PMID: 22800769.


Mathews M, Basil B, Evcimen H, Adetunji B, Joseph S. Mirtazapine-induced nightmares. Prim Care Companion J Clin Psychiatry. 2006;8(5):311. doi: 10.4088/pcc.v08n0510b. PMID: 17245439; PMCID: PMC1780138.


Menon V, Madhavapuri P. Low-Dose Mirtazapine-Induced Nightmares Necessitating its Discontinuation in a Young Adult Female. J Pharmacol Pharmacother. 2017 Oct-Dec;8(4):182-184. doi: 10.4103/jpp.JPP_116_17. PMID: 29472752; PMCID: PMC5820750.


Liliana Dell’Osso, Primo Lorenzi, Benedetta Nardi, Barbara Carpita, Francesca Benedetti, Ivan Mirko Cremone, “Occurrence of Terrifying Nightmares after Few Days of Mirtazapine Use in Elderly Patients”, Case Reports in Psychiatry, vol. 2023, Article ID 8843206, 4 pages, 2023.

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