Marijuana isn't bad for babies? Any mind altering drug (which marijuana is one) can have a significant effect on a child's brain, much more so than a teenager or an adult. Go ask a doctor. My sister's husband is a pediatrician and after your initial post I asked him about it. If it's like a one time thing, then it probably won't have much effect on the child. However, extended use is almost guaranteed to cause learning disabilities such as slower comprehension, dyslexia and extreme short-term memory loss, as well as some long term memory loss in certain cases. Not to mention the damage even a small amount of weed can do to the lungs of a child that small. Heroin was a bad example, I'll give you that, so I'll use something a bit more reasonable. If your child was having trouble sleeping, would you give them alcohol? I mean it's not as though I'm against weed or anything, believe me, I smoke my share of weed (and your share, and his share, and their share, I mean I smoke a lot), but we're talking about a baby here. If the kid was 4, 5, 6 years old it wouldn't be that big a deal, but this was an 18 month old.