Don't quit the Seroquel abruptly -- taper off it. It's interesting you were put on Seroquel and are suffering insomnia -- the only way Valdoxan supposedly works is by increasing the effectiveness of melatonin, which regulates sleep cycles -- in other words, if it works at all for depression, and the evidence appears to be soft, it's by improving sleep. The fact you're taking it for anxiety is also interesting, as it has so far only been shown to be slightly effective for major depressive disorder. So an interesting choice for anxiety. It's not approved for use in the US, so can't help you there. As to your question about your immune system, any drug that sedates you could theoretically lower your immune system. Any drug can also lower your immune system because all drugs are seen as invaders by the body, as they aren't food and our bodies have involved to use food, not drugs, at least not yet. But it could also just be a coincidence or it could be a side effect and you're not sick, you're just feeling like you are because sometimes side effects of drugs feel like you're sick. No way of knowing, really, as people do get sick from time to time and some years are worse than others. Seroquel is not intended to be used for sleep, it sedates people as an unwanted side effect and so the manufacturer sold it for that purpose (illegally, by the way, but it's still used for that). It is possible your system doesn't like the combination. And as I said, if you Google how Valdoxan works, it only works if it helps you sleep and if it isn't doing that to the extent you need Seroquel as well, it could be it isn't being metabolized well by you. I'd discuss this with your psychiatrist and the two of you can make a decision about whether to try something else and see if you stop getting sick. But again, people do get sick, especially when they have small children. As for your body temperature, the differences you're reporting are miniscule, so it appears you might be focusing too much on that part of it.