Hey there! A little bit about me, I'm diagnosed with RBD, Rem-Sleep Behavior Disorder. Basically, I act out my dreams and can injure myself or others in the process. So I was prescribed clonazapam and was told to take melatonin as well. I also had to stop taking mirtazapine, because that is a drug that is well-known for aggravating RBD. This is not good, because RBD typically eventually turns into a neuro-degenerative disease such as Alzheimer's or Dementia, and taking mirtazapine or venlaxafine can speed up this transition.
About mirtazapine: if I didn't have RBD, I would be taking it right now. I have tried several anti-depressants and similar drugs to help with depression and anxiety, and mirtazapine was my favorite of those drugs. It DID make me groggy in the morning, particularly in the first week that I took it. By week four I would still be groggy in the morning, but not nearly as much as in week one. This medication was the only medication prescribed to me for depression that really helped my depression. It also helped my anxiety. There are a couple of interesting facts about this drug. For one, a very noticeable side effect other than morning grogginess and general mild sedation throughout the day was appetite. This is a drug to be taken at night. I have severe insomnia and this drug almost seems better than xanax at knocking me out. That was my favorite effect of the drug. But, back to the appetite comment... when I took this drug at night, about thirty minutes after taking it, I would get fairly severe munchies. Because of this, most people who take this drug gain weight. An interesting fact about this drug is that most users report that they get more sedation from this drug at lower levels, like 15mg or 7.5mg. At 30mg mirtazapine is not nearly as sedating, but it becomes a more effective anti-depressant drug at high dosages. The sedative effects of this drug take effect from day 1, but like most anti-depressants, the anti-depressant part of this drug is not immediate. I believe it takes a month to be in full effect.
A few people mentioned the use of benzos for anxiety. Like I said, I'm prescribed clonazapam and will most likely have to take it for my entire life. I have no problem with that, because this drug is very pleasant. And unlike xanax, it doesn't bring about quick and uncomfortable withdrawals. I mean, the withdrawals can be very uncomfortable, but you'd have to not take clonazapam for at least a week for the withdraw to kick in, so there's usually no reason to worry about clonazapam withdrawals. It is also a drug that works from day 1. It doesn't have to build up in your system. Someone else suggested gabapentin. I'm also prescribed this medication, for restless leg syndrome. This drug helps me with much more than restless leg syndrome, however. It helps greatly with anxiety and depression, and it's sedating but not overpoweringly so like mirtazapine. Btw, IME clonazapam is only mildly sedating. Like gabapentin, the sedation is not overpowering.