Valium is a brand name for the medication diazepam, which belongs to the benzodiazepine class of drugs. It is commonly prescribed to treat anxiety, muscle spasms, seizures, and alcohol withdrawal symptoms. When used for anxiety, Valium helps to alleviate symptoms by acting on the central nervous system and enhancing the effects of a neurotransmitter called gamma-aminobutyric acid (GABA), which has a calming effect on the brain.