Stimulants like amphetamines (speed, meth, crystal), MDMA (ecstasy), and newer designer drugs are among the most popular illegal drugs after cannabis. This work offers a scientifically based and application-oriented overview of the various substances, their increasing prevalence, neurobiological effects, acute effects, and long-term consequences. Explanatory models for the development of consumption and dependence, as well as psychosocial risk factors, are explained in detail. Diagnostics, therapeutic approaches, and concrete intervention strategies are comprehensively described for each substance.