Psychoactive compounds are substances that affect the brain and alter mood, perception, or behavior. These compounds can be found in various forms, including natural sources like plants and fungi, as well as synthetic drugs. Common examples include caffeine, alcohol, and cannabis. When consumed, psychoactive compounds interact with neurotransmitters in the brain, leading to changes in mental state. Some compounds are used for medicinal purposes, such as antidepressants, while others may be used recreationally. Understanding their effects is important for both health and safety.