tory is usually sufficient to identify the relevant substa nce/medication, and follow-up
shows improvement of the sleep  distur bance after discontinuation of the substance/med-
ication. In other cases, the use of a substanc e/medication (e.g., alcohol, barbiturates, ben-
zodiazepines, tobacco) has been shown to exacerbate obst ructive sleep apnea hypopnea.
An individual with sy mptoms and signs cons istent with obstructive sleep apnea hypop-