Zelda has a powerful post about the effects of meth addiction here in NW Arkansas -- her daughter is dealing with it, and so, perforce, is she.
Here's a bit, but the whole thing is worth reading:
[Children] carry cell phones that have no connection because they can at least get 911. Children as young as four will call and say their parents won’t wake up and they are scared. You see, Meth. users tweak for days at a time, when they finally run out of dope, they crash and sleep so soundly that they don’t hear their children crying. [My son] told me just the other night, a little boy called and said he was hungry. The cops got there and found a newborn in the crib with a diaper filled with maggots, the newborn was so malnourished they flew it to a hospital where he could get specialized care.