Why are so many prescription drugs causing terrible, weird or trippy dreams? What causes this?

Not just sleep aids, but even drugs used to help you quit smoking have had numerous reports of and even list bad dreams as side effects.
Do people not even care that what they are taking is effecting them on such a deep level. I'd just love to know what causes this. Is it a chemical reaction? Is it something that is changing in our brains because of the introduced chemicals?
Thanks!

these drugs affect your brain chemistry.. and yes it's a chemical reaction..

so due to that change in brain chemistry, it may cause your dreams to be very odd..

look at illegal drugs.. they cause you to trip.. medications, whether prescription or over the counter, are still a drug.. they are something being put into your body that it's not used too..

for example.. anti depressants and anxiety medications often cause horrible nightmares..

i hope this helps..

I would like to know too.

I recently asked my dad about this... I just started taking Lexapro for depression, and have been having extremely vivid dreams, whereas before I would hardly ever remember having dreams at all.

From what he said, in my case it was caused by a chemical reaction due to the changing amount of seratonin in my brain... or something to do with the seratonin receptors. Maybe that's the case with all those other drugs you mentioned, or at least something similar.