My brother and his ex were hooked on that stuff for several years. I don't know about his ex, but I know he's clean now. While they were using, they lost their house, their cars, their kids to foster care, their jobs-literally lost everything. They scammed people for money, stole things and pawned them etc. to get drug money.
My brother was very difficult to be around when he was on it, he was so crabby and mad all the time. He was paranoid, volatile and mean-especially when anyone confronted him about his usage. He did have times when he'd feel really guilty about it-you could tell, but he didn't care about all the things he lost-that didn't bother him. Until he got clean, that is.
Now, he got clean through the VA hospital, got a government job, left his wife, got a nice car and place to live and most importantly has his kids with him now.
The ex is a mess. She is still on drugs, partying it up, she's pregnant again. Doesn't give a rip about anyone but herself. The drugs do give her that meth rash and she's pretty skinny. She is a miserable person-to say the least.