APA Dictionary of Psychology

any drug that has significant effects on psychological processes, such as thinking, perception, and emotion. Psychoactive drugs include those deliberately taken to produce an altered state of consciousness (e.g., hallucinogens, opioids, inhalants, cannabis) and therapeutic agents designed to ameliorate a mental condition; these include antidepressants, mood stabilizers, sedatives, hypnotics, and anxiolytics (which are CNS depressants), and antipsychotics. Psychoactive drugs are often referred to as psychotropic drugs (or psychotropics) in clinical contexts.