This document summarizes different types of central nervous system (CNS) stimulants. It describes convulsants like strychnine that act by inhibiting the inhibitory neurotransmitter glycine. It also discusses analeptics like doxapram that stimulate respiration. Psychomotor stimulants such as amphetamines are described as producing excitement, euphoria and increased motor activity by blocking neurotransmitter reuptake or promoting release. Hallucinogens can induce changes in thought patterns and mood. The document provides examples and mechanisms of action for various classes of CNS stimulant drugs.