Original sentence: American usage declined in the 1970s and 1980s; this is often attributed to a large anti-drug program targeted at young people in the US
Edited sentence: American usage declined in the 1970s and 1980s, probably as a result of these programs.The United States government began a massive propaganda effort to demonize the drug, often through spreading misleading or patently false memes on its effects in anti-drug education programs in schools