Fox News medical contributor Dr. Marc Siegel on the dangers of mail-ordered ketamine and how using cell phones to calm children can stunt emotional development. Ketamine has become increasingly popular for treating mental health disorders.

But some doctors and clinics have taken it to the next level by delivering the injectable doses to patients — who can then administer the drug unsupervised. Fox News medical contributor Dr. Marc Siegel, who is also a clinical professor of medicine at NYU Langone Medical Center , spoke on "Fox & Friends" on Monday about the dangers of handing out ketamine.

KETAMINE THERAPY SHOWN EFFECTIVE IN TREATING SEVERE DEPRESSION IN VETERANS, STUDY FINDS Ketamine was initially approved for use as an anesthetic in the U.S. in the 1970s, Siegel said.

It was only indicated for treating depression within the last decade. Ketamine was initially approved for use as an anesthetic in the U.S.

in the 1970s and was only indicated for treating depression within the last decade. (iStock) "It works for really severe depression by altering brain chemicals, but under the observation of a highly trained psychiatrist or anesthesiologist," he said. "The idea that it is now available with a little tele-visit, and then they mail it to you with a self-monitoring blood pressure kit, is extremely dangerous.

" "It can make you really, really sick — and without observation, you could end up in the hospital." The physician warned that ketamine can "knock you out, give you hal.