Important to consider if your child is depressed and may need medication is the following:
1) have you tried conservative approaches first, eg therapy, multivitamins with selenium, omega-3 fatty acids? Do not use St. John's wort unless you talk to a physicain first.
2) have you ruled out a physical factor, eg, low thyroid, drug use, medications such as oral contraceptives, antibiotics for acne, etc.
3) if there is bipolar in the family or you suspect bipolar illness in your child, see a child psychiatrist and not your family doctor of pediatrician! It may be more complicated and antidepressants may make things worse.
4) After the above has been considered, then just about any antidepressant should be ok. Prozac has been best studied and is great, so is Zoloft and Celexa. Wellbutrin can be good if there is ADHD also but sometimes isn't as good for depression.
5) though rare, antidepressants can increase suicidal ideation. This seems to occur more in kids prone to bipolar, hence #3 above. If this arises in you child, call your doctor immediately or have your child evaluated at your local hospital ER.
Most of all, invite open dialogue with your child and be observant. Always err on the side of caution and if you feel there is a risk of self harm or suicide, get help!