Final answer:
PCP is an example of a hallucinogen, a class of psychoactive drugs that cause hallucinations and perceptual changes.
Step-by-step explanation:
PCP, also known as angel dust, is an example of a hallucinogen. Hallucinogens are psychoactive drugs that cause hallucinations, perceptual anomalies, and changes in thoughts, emotions, and consciousness. Unlike depressants, which calm the brain and reduce arousal, hallucinogens affect various neurotransmitter systems in the brain, such as the serotonin system for LSD and mescaline, or the NMDA glutamate receptors for PCP and ketamine. PCP does not possess the same abuse potential as stimulants or other classes of depressants, but it does cause profound changes in perception and can be dangerous.