7. theresa started using amphetamines to try to lose weight. after taking them for two months, she found not only that the weight was coming off, but also that she was feeling great and had lots of energy—so she kept taking them. a little over a year has passed, and theresa finds that now she needs to take more and more of the drug to feel any increase in energy or uplift in mood. in addition, if she goes for any period of time without having the drug in her system, she feels awful. these frequently occurring "crashes" are preventing her from spending time with her friends. theresa most likely has a(n): sedative-hypnotic use disorder. hallucinogen intoxication. stimulant use disorder. opioid use disorder.