Acceptance -- first, gain the user's trust and confidence.
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Reduce stimuli -- get the user to a quiet, non-threatening environment.
Reassure -- educate the user that they are experiencing a bad trip, assure
them they are in a safe place, with safe people, and they will be all right.
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Rest -- help the user relax; use stress reduction techniques [such as slow,
deep breathing, or relaxing muscle groups] and let them rest.
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Talk down -- discuss peaceful, non-threatening subjects with the user;
avoid any topic which seems to create more anxiety or a strong reaction.