Which term best describes a person who occasionally uses alcohol or drugs?

The term "casual user" effectively encapsulates the behavior of a person who occasionally uses alcohol or drugs. This designation implies a level of periodic engagement rather than a pattern of consistent or heavy use. Casual users typically consume these substances in social settings or during specific occasions, without developing a dependence or a regular habit.

In contrast, other terms may suggest more habitual or intensive usage. A "frequent consumer" implies regular use, indicating a more significant level of engagement that exceeds occasional use. The term "experiential user" suggests someone who uses substances primarily for the experience or thrill, which may not necessarily reflect an occasional pattern. Lastly, "naïve consumer" could imply someone who is inexperienced with substances, which does not accurately describe the behavior of someone who uses them occasionally. Therefore, "casual user" is the most precise term for describing someone who engages with alcohol or drugs intermittently.