Mirtazapine and Brain Fog: What Users Say

• Gor...
• May 19, 2013

Mirtazapine for Depression "I'm a 43-year-old woman and I've been on 30mg Remeron for over 10 years now. It was prescribed for major depression and generalized anxiety disorder. I was NOT sleeping at all. When I first started taking it, I was a walking zombie for about 2-3 months (got some much-needed sleep), however, after that, it's like someone opened a window in a dark room. I was feeling 80% normal (prior to taking it, I was in the negative). I'll take 80% any day. You should take it an hour or so before bedtime because it has a huge sedative effect. Take care in the beginning because it's potent to begin with. It takes time for it to start really working, so don't be put off by the zombie state, it does go away."

• BBG...
• Taken for 5 to 10 years
• February 14, 2020

For Anxiety "Mirtazapine is the only antidepressant I can tolerate (tried all of the others). I need it for GAD, PTSD, and insomnia. My usual effective dose is 30mg, but I can either go up to 45mg or down to 15mg depending on where I’m at. It 'can' make you put on weight, but it doesn’t have to if you watch your diet and exercise. Also, be aware when the carb cravings hit, try to be mindful and have some protein instead. The fog should wear off after a few weeks. I find going to bed an hour earlier most nights helps waking up a bit easier."

• Ano...
• Taken for 10 years or more
• April 23, 2025

For Insomnia "I was on Remeron 15 mg, but would take 7.5 for sleeping. I would get brain fog during the day, so I slowly weaned off of it by taking tiny quarters and then tiny bites. I could not sleep for a week! Only about 3 hours a night. I was struggling with work and laid around when I wasn't working because I had no energy. I tried melatonin and Tylenol PM, with no success. Last night I gave in and took a tiny bite of Remeron, and after 5 minutes my brain relaxed, and I fell asleep for 8 hours!! OK, I admit it, I have to take it to sleep, even though you are not supposed to take it as a sleep aid. I never want to feel sleep deprivation again! It was the worst feeling ever!"

• Ash...
• Taken for 1 to 2 years
• July 11, 2019

Mirtazapine for Depression "Terrible! Never again. I gained 13 pounds, and I'm normally a small person. You gain every few months. I felt like I was in a fog the whole time with no personality, and I didn't realize it until I got off. I refused to gain more weight and told them I'm getting off it. They told me to just stop taking it. DON'T! I did since they said to, and my anxiety spiked to a 10, and after a few weeks, I had a nervous breakdown. I also had insomnia for months and slept maybe 2-3 hours a night for the first two weeks until I said put me back on so I can wean myself off safely - the right way. It's been about 5 months off, and I still have insomnia, which could be lifelong. No one told me I would be addicted to this med."

• bre...
• Taken for 1 to 6 months
• June 23, 2014

For Insomnia "Mirtazapine can work wonders for anyone struggling with insomnia, in my case caused by anxiety. Significant improvement from day 1, and has persisted for my 6 months of treatment. You'll feel like a zombie for several days, but don't let that bother you. After about a week or two, I was able to wake up at my normal time and feel good heading into work. Perhaps some benefit, although less noticeable for anxiety in general. But again, for insomnia this is a lifesaver. Went from 157 lbs to 164 but I've also been lifting weights and working out more, so no issue there. Good luck!"

• Mni...
• Taken for less than 1 month
• January 22, 2020

Mirtazapine for Depression "I was prescribed 7.5 mg Remeron along with 50 mg of Zoloft. I've only taken two doses, and it left me in a zombie state for two days. I slept, but I slept from 11 PM to 11 AM, which is obviously unrealistic. Even after I woke up, I felt out of it, as if I was on drugs almost, and was exhausted all day. I also felt like my thinking was off and like I couldn't even form a sentence, it is very terrifying. It is almost like my brain can't process what is going on in front of me, even my vision felt off. I don't plan on taking this anymore."

• AJM...
• March 14, 2015

For Insomnia "Mirtazapine has been a lifesaver for me. I have had trouble falling asleep on and off over the last two and a half years, mainly because I've been unhappy at work. Just recently, I was on zolpidem for 2 months and then switched to mirtazapine when I realized my sleep problems weren't going to get better in the short term. A couple of years ago, things were so bad that sleeping tablets didn't even work, and mirtazapine was the only medication that got me to sleep. I function normally after about the first 8 days of adjusting to this tablet - day 1 I feel like a zombie, but by day 3, I start to feel less like that. Just stick with it for a few days, and you will adjust, is my advice. The dosage I take is 30mg or 45mg."

• dep...
• February 13, 2020

For Insomnia "This medicine is horrible for insomnia. I have tried it, and yes, it knocks you out and lets you sleep and stay asleep for 9-12 hours... but the side effects are horrible: you will feel like a zombie for the next 5-6 days."

• JeN...
• Taken for less than 1 month
• January 8, 2023

Mirtazapine for Major Depressive Disorder "I am an addict. I started taking Remeron at Recovery Works about 4 weeks ago. I have always had trouble sleeping due to many, many years of drug use, so they started me on 15 mg. It wasn't working, so my dosage was increased to 30 mg. Within 20 minutes after taking it, I am ready for bed. I still wake up 1-2 times every night, but I have had no trouble falling asleep whatsoever. Also, my craving to use has dramatically decreased. I don't feel like I am dependent on it, but I definitely want to take it every night before bed. My appetite and weight have remained under control and normal. I do feel a little 'foggy' in the mornings, but it usually subsides, and I am not drowsy or tired throughout the next day. This drug was the answer to my insomnia. Definitely a plus for people in recovery."

• Mat...
• Taken for less than 1 month
• May 2, 2020

For Anxiety "I took 15 mg of mirtazapine after dinner at 7:50 PM... fell asleep by 9 PM and tried getting up at 5 AM as I had an early start. I couldn’t even sit upright, I was so drowsy with it, so I collapsed on the sofa and checked my watch, which showed a heart rate in the early 30s! It’s like a sedative. It’s now 24 hours later, and I have more or less slept all day and still feel zoned out, but recovering. Maybe my body needed the rest, but I won’t be taking the rest of the 10-day course the doc gave me."

• sle...
• Taken for 1 to 6 months
• August 25, 2013

For Insomnia "I love Remeron so far. I have been on so many sleeping pills since I began to have terrible insomnia 3 years ago. I was taking Seroquel at 50 mg but it took forever to put me to sleep and made me foggy during the day. I switched to Remeron 15 mg two months ago, and it works a lot better. It will make you hungry after you take it and you will feel foggy the first couple weeks, so tell your doc to start you off slow, maybe 7.5 mg at first. I have had a few pounds put on me but I am eating more and I stopped exercising, so that might be it. On Seroquel I tried to eat healthier and exercise and I gained 12 pounds on it anyways. Remeron works way better and helps with depression and anxiety too, it also gives me very vivid dreams."

• Spe...
• September 1, 2019

For Anxiety "Have been on 15 mg mirtazapine for 2 weeks. Second try on this drug. Shaking. Trembling. Nauseated. Exhausted and zombie-like. Panicky. Rapid heartbeat. Freely agitated and angry. Keep clear of this. Want my Zoloft back."

• dep...
• Taken for 1 to 6 months
• April 19, 2023

For Depression "Infection caused my sertraline (Zoloft) not to work for a while. Was then put on mirtazapine 15 mg. It worked to a point, but that could have also been because the infection cleared and sertraline was working again. This was after 2 weeks. However, week 3 was when the sedating effects occurred. Sleeping 17+ hours a day, staying in bed 23 hours due to being unable to function (zombie-like feeling) and not physically or mentally being able to get out of bed in the morning. This lasted for around 7 days before I spoke to the doctor and was advised to stop straight away. Lucky I have been signed off work for a few weeks, which is not good due to the nature of my job. The other side effects I got from the drug were feelings of no emotion, no sadness, no happiness, could not cry, felt drained, nothing. Insomnia from withdrawing is still occurring 2 weeks after stopping. Would avoid."

• Anonymous
• Taken for 1 to 6 months
• September 25, 2022

For Anxiety "I have been struggling with anxiety and lack of sleep (waking up having panic attacks, etc.). I’m a 46-year-old female and also have ADHD. So, in a nutshell, I started mirtazapine at a very low dose to test it out. I started at 7.5 mg but felt zonked the next day, so I halved that, and this works for me. I have slept all night for 2 months now. I still only take 3.25 mg, which is half of the 7.5 mg, half an hour before bed, and I sleep all night. No anxiety either now. Occasionally, I wake to go to the toilet, but I go straight off again. It’s been amazing for me. I read all sorts of reviews on here that put me off - weight gain, etc. Maybe that’s at higher doses. If anything, I’m eating a little less. I have more energy, and probably because I am sleeping 8 hours a night. My mother-in-law also takes this, she’s 72. She is on 7.5 mg for anxiety, and her doctor has said she doesn’t ever need to stop because the benefits are so good. Go for it."

• Mam...
• Taken for less than 1 month
• May 22, 2016

For Major Depressive Disorder "I have fallen in love with this med! My cyclic depression was at an all-time high, suicidal ideation, hopelessness, severe anxiety and paranoia, insomnia, and ready to literally give up on life. I started on 15 mg for the first 2 days. It knocked me out, and I slept very well. Bad side effect was being super groggy all day long and a little foggy. Not a big change in depression until the third or fourth day. I upped the dosage to 30 mg on the third day, and after a week, I am feeling so much better! It doesn't completely knock me out right away like the first night but just makes me a little tired. I wake up ready to face the day and happy. The dreams are a little crazy, but they're kind of just like fun adventures. I recommend this drug!"

• Fla...
• June 19, 2021

For Anxiety "I thought I would share my positive experience for anyone that needs to hear it. 8 weeks after having my second baby, I started experiencing postpartum anxiety. I contacted my GP straight away and started therapy and meditation (Headspace). The anxiety was somewhat manageable until it started to affect my sleep. I was awake for 3 days in a total state of panic. I slept on the third night but started to experience uncontrollable panic about sleeping. I contacted my GP, who recommended mirtazapine 15mg. The first couple of weeks, I felt foggy and zoned out until the afternoon, so I thought I would ask my GP if I could take 7.5mg and told him about how anxious I was as I have read it is more sedating at lower doses. He agreed to halve the dose, so I did this for one night, and let me tell you it was not more sedating, and I felt anxious the next day and resumed taking the 15mg the next night, and I’ve stuck with that dose for the past month with minimal side effects."

• Fla...
• June 19, 2021

For Anxiety "I thought I would share my positive experience for anyone that needs to hear it. 8 weeks after having my second baby, I started experiencing postpartum anxiety. I contacted my GP straight away and started therapy and meditation (Headspace). The anxiety was somewhat manageable until it started to affect my sleep. I was awake for 3 days in a total state of panic. I slept on the third night but started to experience uncontrollable panic about sleeping. I contacted my GP, who recommended mirtazapine 15mg. The first couple of weeks, I felt foggy and zoned out until the afternoon, so I thought I would ask my GP if I could take 7.5mg and told him about how anxious I was as I have read it is more sedating at lower doses. He agreed to halve the dose, so I did this for one night, and let me tell you it was not more sedating, and I felt anxious the next day and resumed taking the 15mg the next night, and I’ve stuck with that dose for the past month with minimal side effects."

• Anx...
• Taken for less than 1 month
• September 24, 2024

For Anxiety "I suffered with a mental health crisis in June 2024 when Citalopram 40 mg just gave up on me after 20 years! So I was a wreck, the doctor thought it was hormones, so he gave me progesterone tablets for 7 weeks, which made me very depressed. The doctor then realized that it could be Citalopram not working, so he reduced me overnight from 40 to 20 and added mirtazapine 15 mg. From the first tablet, I felt it working. Yes, I was a zombie for 3 days, but my sleep and anxiety improved. I’m now on week 4 and will increase to 30 mg mirtazapine and 10 mg Citalopram. I’m hoping this will be my perfect dose and I can return to work and enjoy life."

• Mik...
• Taken for less than 1 month
• May 2, 2016

For Depression "My first week experience taking Mirtazapine 15 mg nightly. Night 1 - Slept for 14 hours straight. Woke up groggy, mind foggy with dry mouth, lethargy, and a voracious appetite. Not a good start. Nights 2-4 - slept really badly each night. By day 5, I felt like a zombie, slurring words and forgetting even the basics like people's names. Thought about calling the doctor and getting off this medication. Nights 5-7 - decided to take medication an hour before bed (instead of just before bedtime) BIG improvement. Woke up day 6 feeling refreshed, clear of mind, and full of energy. Still had the appetite and dry mouth, but I wanted to do things and the things I always enjoyed doing! Great feeling. This seems to be working for me. I will continue taking it."

• jus...
• February 9, 2020

For Anxiety "Prescribed mirtazapine for anxiety, sleep, weight loss, and acid reflux pain. 2 months, 3/4 of a 30 mg tablet and still sleeping 9 to 10 hrs per night. Brain fog is still present, but I don't feel completely impaired. Anxiety is returning, and I feel emotionless. I also feel like I'm at 90% mental clarity, and I get random moments of fatigue and the desire to nap. My weight is slowly coming back after dropping 20 lbs in two months. Med leaves you trapped in your own body for two months: dazed, blurred vision, and exhausted. It helped me, but at the cost of freedom, work, relationships."

• Cha...
• Taken for 6 months to 1 year
• March 25, 2019

For Insomnia "Doctor put me on Mirtazapine 15 mg a night for insomnia, as he didn't want me staying on Zolpidem for a long time. The Mirtazapine does work well, but if I don't take it, I am awake all night. I don't want to rely on a drug to sleep, but what can I do when Mirtazapine works well? I guess it's better than no sleep and feeling spaced out the next day."

• Zar...
• Taken for 1 to 6 months
• August 7, 2013

For Depression "I have suffered from severe depression over the past 12 years and was on citalopram, which was not controlling my depression at all. Now, having had my meds changed two months ago, I am like a new person-no, I am like how I should be. I had a change in my mood after less than a week, and now I can look forward to a hopeful future. Unfortunately, I did suffer side effects, including very weird vivid dreams, feeling exhausted, confused, dizziness, vertigo, and increased appetite. All of these symptoms have now subsided, and I feel they were worth battling with to get to where I am now. However, I would not have been able to work during this period or make responsible decisions. Overall, I would recommend."

• jep...
• Taken for 6 months to 1 year
• February 3, 2020

For Insomnia "For the first 2 months, mirtazapine probably helped me with insomnia with a dose of 7.5 mg, but it made me groggy and caused brain fog. It's also very difficult to quit because withdrawal symptoms are terrible (insomnia, anxiety, increased tinnitus). Also, mirtazapine causes significant weight increase, so if you are already overweight or close to being overweight, then I wouldn't recommend this medication."

• amy...
• Taken for 6 months to 1 year
• October 19, 2017

For Insomnia "Consider mirtazapine if you have intractable insomnia. I'm a recovering alcoholic, and my sleep patterns got thoroughly screwed up during my drinking years. Mirtazapine 30 milligrams provides the most natural sleep I have ever had in my life. I sleep for eight hours and wake refreshed the way I did when I was a teenager. It's so much better than benzos. Doctors may be reluctant to prescribe because of the chance of weight gain. I did gain weight because it gave me the munchies. But it leveled off at about a 7-pound gain. But it did level off! And you may feel completely zonked for the first two or three days. It's a good idea to start on the weekend. But again, the extreme drowsiness did disappear after a few days for me."

• Jus...
• Taken for less than 1 month
• October 29, 2019

For Depression "I know everyone reacts differently to meds, and I'm glad this has helped so many, but for me, mirtazapine has been a nightmare! So spaced out, lethargic, diarrhea, headache, chest pain, vision disturbance, and more. Was taking 15 mg once a day. No more! I can't take SSRIs or SNRIs, so my doc tried this. Never again! This is horrible!!!!"