Question

person who abuses more than one drug at a time
polyabuser
hidden observer
tolerant abuser
withdrawn abuser
psychotic user

Explanation:

• "Polyabuser" is a term used to describe a person who abuses more than one drug at a time.
• "Hidden observer" is a concept in psychology related to dissociation.
• "Tolerant abuser" is not a standard term for this specific description.
• "Withdrawn abuser" does not convey the meaning of abusing multiple drugs simultaneously.
• "Psychotic user" refers to a user with psychotic symptoms, not specifically multiple - drug abuse at once.

Answer:

polyabuser