Depressants generally have the opposite effect of stimulants. Many depressants are used as sedatives or tranquilizers, terms often used as if they mean the same thing even though some experts would dispute such interchangeable usage of the terms sedative and tranquilizer.
Depressant drugs slow a person down, and one result can be reduction of tension, which in turn can improve a mentally depressed mood. Depressant withdrawal symptoms typically include uneasiness and sleeping difficulty. If dependence is strong enough, withdrawal may also involve tremors, loss of strength, delirium, and seizures. Gradual reduction in dosage may help avoid withdrawal symptoms, but much depends on the particular drug and the strength dependence.
For information about specific depressants not listed among the following classes, see alphabetical listings for: alcohol, chloral hydrate, ethchlorvynol, GHB, glutethimide, ketamine, mandrake, meprobamate, methaqualone, PCP, pentazocine, zaleplon, and zolpidem.