I myself have never been on lithium, I was told that it doesn't have the same effect the second time around if you stop taking it and start it again later. I've heard that positive effect may decrease the second time you use it. I would ask you doctor about this. Lithium also requires routine blood work tests. Lithium is a natural chemical produce by the body, maybe the brain, I am not sure. Having too high a level of lithium can potentially cause brain damage. I suggest you ask your doctor about all risks including risks of accidental overdossage, like if you forgot you took your meds and then took them again. Or what the risks are if any if you miss a dose. I used to have a problem missing doses of my meds. Not everyone has that problem, but if you do, I would ask. Good luck. I wish you the best.
benzo's and lithium are altogether different thing. the latter is an ms for bipolarity say but the first is a tranquiliser
I've taken Klonpin which is the medication with the most mood stabilizing effects and it wasn't very strong. Good for anxiety though. If I was having troubles I'd choose lithium (I can't take it because I only have one kidney). Although there are other mood stablizers out there such as Depakote and Lamotrigine. I take lamotrigine. Fairly low side effect profile, fairly weight neutral, although my understanding is it is better for bipolar depression and Lithium is better at controlling manias. I don't know much about Depakote. I don't think it is used as much now.
If you don't see a psychiatrist I'd get a referral to one when you see your GP on Monday. Since they are addictive I would be very surprised if your doctor gave you benzo's for long term therapy. Especially if this is for bipolar and not anxiety.
From what I am aware of benzodiazepines only have a mild mood stabilization effect (I have had them prescribed for anxiety issues but they never had a full mood stabilization effect) and lithium is a first line mood stabilizer and generally would be the one choice used before the other but you could speak to your psychiatrist about this.