I saw that program a few months ago. I'm not anti-medication but I am VERY wary of pushing drugs on young children for the same reasons you listed. Children's brains are have more plasticity than adult brains, so occupational therapy, behavioral therapy, counseling, etc could possibly alter their brain functioning in a much safer and more natural way.
What really disturbed me was the way some of these doctors pushed drugs without considering options first. They profiled a young boy diagnosed with bipolar. They showed him and his mother during one of his doctor visits his mother said something like, "He (forgot the child's name) throws temper tantrums before we take him to school but once he gets there he's fine." So the psychiatrist decides to add Xanax to his daily medication regimen!

WTF! Then the mother asked, "Is there ANYTHING ELSE I can do? Like taking a class? Anything?" And the psychiatrist immediately said, "No, I think at this point it's 98 percent biological!" He didn't even bother to try any therapies!
They also profiled another girl who was diagnosed with bipolar at age four who is now 13 years old. During one of her doctor visits her mother reported she had been acting depressed so the doctor decided to increase her medication which was ridiculous. First of all, she's a TEENAGER! What teenager DOESN'T act emotional or moody? Most importantly, her father had recently been sent to IRAQ! The poor kid probably missed her father and was worried about his safety. Of course she's not going to be cheery under those circumstances. They could have tried counseling to help her deal with her dad and other problems in her life.
I think medications should be used as a last resort. Medications can be lifesavers for people who actually have chemical imbalances but I'm very worried that doctors and consumers are using them to numb emotions instead of allowing children to experience these natural emotions and learn from them as they grow up. They're not learning to deal with their emotions if you just give them a pill. In the rare case when a child truly needs medications, the pills should be prescribed IN CONJUNCTION WITH OTHER THERAPIES as well. Medication should be used as a tool to help a person deal with his/her life, not as a way to suppress the symptoms.