This is only my opinion but prescribing SSRI's for children under 18 is risky business even if the dx of bipolar is correct. Plus, if you give someone with bipolar an SSRI (Zoloft) you MUST also give them a mood stabilizer such as depakote or lithium or they will most certainly have more mood swings into manic or hypomanic states. SSRI's w/o mood stabilizers will induce mood instability. I would go back to that doctor and question the medications and specifically ask about a mood stabilizer.

PS. I've been bipolar all my life and i'm 58 years old and medicated successfully.

Best of luck to you and your daughter.