My son is bipolar and 18 years old.  I am curious - what are
"normal" lithium and depakote levels?

Dear Liz -- 
Depends on what kind of bipolar disorder he has.  If it's "bipolar I", with full manic episodes and depressive episodes, but "back to his usual self" in between, then you have to use the lithium level to predict whether he's taking enough to prevent a recurrence of episodes.  Whereas for bipolar II folks who have symptoms all the time, levels are much less important -- one just treats until the symptoms disappear (and then after the person has enjoyed a period without symptoms, we cautiously and slowly begin to taper some of the medications it took to get there, hoping to discover how little medication we can get away with and not see symptoms return).  We use lithium levels in the latter context to make sure it's not too high, but as long as it's not 1.1 or greater (some would say 1.3 or greater, and some would get nervous even around 1.0), which is getting into the "too high" range, we'd not worry much about what the exact level was. 

And conversely, in bipolar I, as above, one wants to see the level above 0.7 (some would say as low as 0.5 is okay) to be sure he's getting sufficient protection from a recurrence, as there are a few studies comparing the risk of recurrence at different levels: they seem to show a "threshold" for recurrence below that 0.7 mark. 

So that defines the lithium "therapeutic range": 0.7 to 1.1 (or 0.5 to 1.2 according to some).  There is no "normal" as such, if you follow me.  

Depakote levels are even less well defined.  It looks like most people won't see much effect, at least for bipolar I, below a blood level of 50.  And there are some that require a level up to 125, but beyond that one sees mostly side effects and not many people who finally start to respond as the doses go way up there (3000mg might be required for some to get levels that high, for example).  

Published May, 2001