what does the least harm to teens?!

no drugs are good for teenagers! Even marijuana can cause lasting damage, especially 'skunk'. Teens brains do not fully form until they are 21 years old. The frontal lobes (which control behavior and reasoning) are the last to form, so the introduction of anything that alters perception can have lasting damage. There are several studies that have shown the introduction of 'skunk' before the age of 21 can trigger the onset of schizophrenia. There has been a huge increase in depression and anxiety disorders over the past twenty years and this has been linked to smoking skunk. This problem has been identified in the UK and has led to the first new mental health disorder to be identified in over sixty years, 'marijuana induced psychosis' and the figures are showing that at least 25 percent of skunk users under the age of 25 will be affected by the disorder.

i would say heroine? but only if it is from a shared needle.. those sterile needles can really mess you up. Meth is pretty decent too. So much stuff you can get done!!! stay away from pot though. Marijauna is a gateway drug. Yes, a gateway to HELL! jk...

Alcohol.

Marijuana. Stay away from other drugs!

Umm... none!

But if you're an adult I'd say weed or alcohol.