As a result of medical treatment or recreationally? Assuming the latter and a popular choice of recreational drug, I don't much harm will come from a kid seeing

As a result of medical treatment or recreationally? Assuming the latter and a popular choice of recreational drug, I don't much harm will come from a kid seeing a friend's parent saying stupid things and eating snack foods. If the friend's parent was visibly drunk, that would be something to worry about.