What is a clinical manifestation of hallucinogen abuse?

Hallucinogen abuse is primarily characterized by the alteration of perceptions, thoughts, and feelings, leading to experiences such as hallucinations and flashbacks. Hallucinations involve seeing, hearing, or sensing things that are not present in reality, significantly affecting a person's sensory perception. Flashbacks, which are spontaneous recurrences of these hallucinations after the drug's effects have worn off, can occur days, weeks, or even months later. These manifestations are distinctive to hallucinogen use and can lead to confusion, anxiety, and distress in individuals who experience them.

In contrast, increased respiratory rate does not directly relate to hallucinogen use; rather, it may be associated with stimulant drugs or anxiety conditions. Weight gain generally does not connect with hallucinogen effects, as many hallucinogens may actually suppress appetite. Constricted pupils are typically linked to opioid use rather than hallucinogens, which can often cause dilated pupils.