Large pupils, sticky mouth, wide opened eyes, glazed, glassy eyes, walking funny somewhat like stomping, slurred speech (unlike an alcohol slur, this is mostly a result of numbness
in the tongue
as I remember it), inability to sleep for at least 8 hours after ingestion (usually), loss of appetite.
Make no mistake, this drug is for real. It is actually quite popular among teenagers. My only advise is to talk to a doctor and do what you think is best as a parent.