Psychoactive drugs are substances that affect the brain and alter mood, perception, or behavior. They can be found in various forms, including prescription medications, over-the-counter drugs, and illegal substances. Common examples include caffeine, alcohol, and marijuana. These drugs work by interacting with neurotransmitters, which are chemicals that transmit signals in the brain. The effects of psychoactive drugs can vary widely, ranging from increased energy and alertness to relaxation and euphoria. However, they can also lead to negative consequences, such as addiction or health issues. Understanding the impact of these substances is important for making informed choices about their use.