Are diet drinks causing health problems and should they be the only choice of soda drinks in school vending machines?

I found this article http://www.huffingtonpost.com/dr-mercola/aspartame-health-risks_b_668692.html and it has much information on aspartame. It brings into question the possibility that aspartame is actually a neurotoxin. I have seen my sister and two friends battle headaches and still consume diet drinks at the rate of 3 to 5 a day. Then they take medication for the headaches. Other problems have been reported with aspartame such as obesity and depression. Also there are scientists who feel “that in sensitive individuals… excessive aspartame ingestion might be involved in the pathogenesis of certain mental disorders (DSM-IV-TR 2000) and also in compromised learning and emotional functioning.”
Do you feel that soft drinks with any chemical sweetner should be in our schools or be the only soft drink option in vending machines as is often the case?