Hi boldchexmix. I have to say that I don't quite remember. The first time I was on Lithium ER I took 1200 mg per day (600 mg morning and 600 mg night), along with maybe 50 then up up up mg of Seroquel. I don't recall being sleepy from it at that dose.

A handful of years later I was on a huge cocktail, including 900 mg of Lithium ER. I think I took 300 mg in the morning and 600 mg at night. I have to admit that initially I was depressed so was tired, but then later I was hypomanic/manic for months on end, with no fatigue in the morning at all.

Sometimes it's difficult to know whether a medication is making you tired or the illness itself, but other times it's obvious. I wouldn't say that Lithium ER is a major sedating med. Antipsychotics like Seroquel are much more notorious for that.

I can say with certainty that Seroquel can cause a "hangover" in the morning, especially at doses like you're on. My advice is to not take it too late in the evening, and to get a lot of sleep. Sleeping only 6 hours per night is just not enough for me on Seroquel.

As an FYI, for me, larger doses of Seroquel XR (which I currently take) do not sedate me much more than lower doses like 200 mg. I do think that when I took up to 600 mg of the regular Seroquel that it gave me a hangover in the morning. The regular affected me a bit differently than the XR in terms of sedation. The regular's "spike" as I call it can be especially rough. While I don't think the XR has such a spike, it is more even throughout the whole day, while I did find the regular to wear off more quickly, but obviously at large doses of 600 mg not so fast.

I'm betting that over time you will adapt to the meds and you won't be as tired in the morning, as long as you're not experiencing depression fatigue.