Ten years ago, stimulants like Ritalin and Adderall were the drugs of choice to treat behavioral issues in children. Today children as young as four years old are being prescribed more powerful anti-psychotic medications that are much less understood. The drugs can cause serious side effects, and virtually nothing is known about their long-term impact. The increase in the use of anti-psychotics is directly tied to the rising incidence of one particular diagnosis - bipolar disorder. Experts estimate that the number of kids with the diagnosis is now more than a million and rising. As the debate over medicating children continues to grow, FRONTLINE producer Marcela Gaviria confronts psychiatrists, researchers and big pharma about the risks and benefits of prescription drugs for troubled children.