Are nootropics a separate class of drugs? A differentiation in various models

Psychostimulants, analeptics, and nootropics are three classes of drugs that have been used with varying success in the treatment of impaired brain functions. They all produce an excitatory and disinhibitory effect on the CNS but can be distinguished through their characteristic properties. Psychostimulants are drugs that lead to a general, but nonphysiological activation, which is followed by a phase of inhibition. Analeptics are drugs that stimulate the CNS, in particular the respiratory and circulatory centers, and which in high doses lead to convulsions. Nootropics are drugs that (in impaired brain functions) lead to a physiological activation of adaptation.