+A **psychoactive substance** is a chemical that alters brain function, affecting perception, mood, and consciousness. These substances, including [Drugs](/wiki/drug) and [Medication](/wiki/medication), can significantly impact mental states by acting on the central nervous system.
+## See also
+- [Addiction](/wiki/addiction)
+- [Neurotransmitter](/wiki/neurotransmitter)
+- [Brain](/wiki/brain)
... 1 more lines