Complex sentence: The Drug Enforcement Agency, and the National Institute on Drug Abuse are highly respected and well established; that two such different bureaucracies have responsibility, for addictive drugs suggests that there is something amiss in the Americans response to addiction.
Split into simpler sentences: The Drug Enforcement Agency, and the National Institute on Drug Abuse are considered by many to be high respected. They view that addictive drugs suggests that there is something amiss in the Americans response to addiction.