Is it true that Some tranquilizers are stimulants that speed up the central nervous system?

No, that statement is not true. Tranquilizers, also known as sedatives or depressants, work by slowing down the central nervous system, leading to effects such as relaxation and reduced anxiety. Stimulants, on the other hand, increase the activity of the central nervous system and elevate alertness and energy levels. These two categories of drugs have opposite effects on the body.