John McKay, a Menlo-Atherton High School student who was a nationally ranked debate champion, used a credit card to purchase 90 capsules of fluoxetine, the generic name for Prozac.
His father, David McKay, a professor of structural biology at Stanford University, said there were no obvious signs of depression, the San Jose Mercury News reported.
The pharmacy McKay used, USAnetRX.com, does not require a faxed or mailed prescription from a licensed physician, as many other mainstream online pharmacies do.
Instead, USAnetRX.com asked patients to submit an online questionnaire to be reviewed by one of its physicians before dispensing the drug.
A Colorado doctor, psychiatrist Christian Hageseth III, whose medical license had already been restricted, reviewed his questionnaire, which said the drug was needed for adult attention deficit disorder and "moderate" depression.
Anti-depressants now carry the FDA's strongest "black box" warning, which notes the link between anti-depressants and suicide in children and adolescents.
Notable deaths of 2014 [PHOTOS]