Substances and Effects How do drugs impact our brains and bodies? And why would someone want to use them? From OxyContin to heroin, learn how opioids affect the body, how to spot misuse, and how to reduce risks. Learn how to identify an alcohol use disorder and how to reduce risks when drinking. Learn how these drugs affect the body, and how to spot a cocaine overdose. Medications like Xanax and Valium are effective but can be dangerous when misused. Learn about their effect on the body, the risks of misuse, and the potential for medical use. Learn how marijuana affects the body, how it can be used medically, and how to treat a marijuana addiction.