I assume a speedfreak is a tweaker. Let me know if I'm wrong. It's the first time that I've heard or read it. Do you have any idea how it was derived?
No idea where it came from. Just street slang. There is some base-level community-of-interest among people who are down-and-out in a city. But nobody likes tweakers (or 'tweekers'). They would steal from their own mothers in a heartbeat. The drug owns them, in a way that not even crack owns people.
I forgot to answer that part. I'm not sure there is an Official Dictionary for words like crackhead, speedfreak, and tweeker. I would draw a distinction for my own use. To me, "speed freak" includes people who take, oh, Dexamyl or stuff like that, for the rush. There are probably people who do that, who have jobs and are functioning. "Tweeker" is a derogatory term on the street, referring to the ones that cannot function except to relentlessly pursue the next hit. It's not Dexamyl they want, it's crystal meth. They are usually paranoid in the way that schizophrenics are often paranoid. The phone company follows them around; the CIA is after them; FBI snipers are waiting in the park to kill them. They come across as "nuts" the first time you meet them, and so they cannot get or hold jobs. They are broken people with broken brains. They will never do anything with whatever promise they once held. The will lie and steal their way to the next hit until they die, looking like that woman in #15.
I presume there are people who get on that stuff and somehow pull out of it. But others are rendered psychotic the first time, and they never come back.
Yes. Speed affects the entire body. When a person's body has used up most of the drug, their muscles begin to spasm, or twitch.
In Austin they call them tweekers or crack whores.