The reason lungs get screwed up in smoking is because of the tar in smoke, most often cigarette smoke. It hinders the lungs' own cilia and destroys them and particles just build up in the bronchi and bronchioles of the lung. Then you've got replacement scar tissue forming and some of these can be cancerous when they replicate at abnormal rates to offset the damage. I don't believe that eating things with psychoactive drugs can affect your lungs since you're not taking it in through your lungs and they're ingested in your stomach to release the psychoactive agents that affect the neurotransmitters in your nerve cells only.
If you smoke something for a long time, or do something that's natural to you for a long time, then of course it can be psychologically addicting and you'll most likely suffer from withdrawal and social dependence. However, cannabis is not physically addicting, and people can already be predisposed of being psychologically dependent on it in the first place.
Meth and cannabis are two completely different drugs. Meth is a drug that will cause physical addiction since it actually decreases the concentration of certain neurotransmitters in the nerves permanently.
If you smoke something for a long time, or do something that's natural to you for a long time, then of course it can be psychologically addicting and you'll most likely suffer from withdrawal and social dependence. However, cannabis is not physically addicting, and people can already be predisposed of being psychologically dependent on it in the first place.
Meth and cannabis are two completely different drugs. Meth is a drug that will cause physical addiction since it actually decreases the concentration of certain neurotransmitters in the nerves permanently.