Add : Caving in to peer pressure
IMO you should have put Opiodes/Illicit drugs together.
Opioids by far. Opioids USED be what was in the news most often as a concern of parents, politicians and public health - but for some reason the fears of products with far less potential for harm (like "vaping") has taken over as the "cause of the day".
Quick stat: In 2017 - per the National Institute on Drug Abuse, 72,000 people died from opioid overdoses. Based on how many people are wringing their hands over kids "vaping" I have to ask - how many have died from using an e-cigarette?
Parents should prioritize their worry based on ACTUAL risks, rather than perceived risks; that's why I chose opioids over all other options listed.
Opiods, Alcohol and drugs are extremely dangerous and worry some as a parent. Vapor is not even in the top 20 of things to worry about.
Kids who drink seem to do so right through life sometimes in huge amounts. Pot is not as addictive as booze so I see no huge issues with it. Kids who drink and drive have higher rates of accidents I believe.
Illegal drugs require you to be motivated to work to support that habit and I haven't seen too many kids under 18 doing that either. So for my buck booze is easiest to get and abuse or use daily just like cigarettes!