I can't do it anymore :(

I've had the ability to lucid dream ever since I was a child. I wouldn't have to force it, it would just happen sometimes. On average I'd probably get one once a fortnight. Three months ago my doctor prescribed me mirtazapine for my depression, anxiety and insomnia (it used to take me HOURS to fall asleep) I'm sleeping a LOT better but I haven't had a lucid dream since I've been on them :( I'm also remembering a lot less dreams. I must be sleeping deeper than before. My anxiety and depression seem to be improving too :) I just think I may need to take 30mg instead of 15mg, I'm going to make an appointment with my doctor about it soon.

Could I start having them again? Or will I have to deal with not having them?

You can adapt and have them again. It will likely happen much faster if you work on having them and doing WBTB (waking up after at least 4.5 hours and then going back to bed).

If you find it hard to become lucid lately, then I would recommend you to not focus too much on actually becoming lucid, but to set less demanding goals that can encourage lucidity, for example recalling your dreams as much as you can in the mornings and becoming familiar with them.
I believe that simply trying to be as present as possible in your dreams - in other words, deciding as you fall asleep that you will experience the dream as much as possible - can be a very effective way to become lucid without directly aiming for lucidity.

Sometimes it can also be a good idea to take a break for a couple weeks or so - when I do that myself I tend to feel a renewed excitement when I start thinking about lucid dreams again.
I always say that lucid dreaming should never be frustrating, it should be exciting and motivating.

It's also totally natural to have dryspells.
Yeah they suck, but they happen to most lucid dreamers, and it's not unusual that they sometimes last for a few months.
But keep in mind that your next opportunity to become lucid will always be the next time you go to sleep.

Hi Conspiracy. I've been on anti-depressants in the past and they always have side effects. You could speak to your doctor about the situation. He/She may have some suggestions.

I did a quick online search and found an antidepressant which may not have a negative impact on REM sleep and dreaming: Citalopram. You can ask your Dr. about this medicaton or do some research yourself to find something which may work better for you.