Here's an article going back to 2003: http://www.opioids.com/offshorepharmacy/deapaindoc.html
Here's one on 2004: http://doctordeluca.com/wordpress/wod-pca/
Doctor's opinion from 2008: http://www.healthcentral.com/chronic-pain/c/91/46424/prescri...
A briefing to congress from 2004, contains many useful references: http://www.aapsonline.org/painman/paindocs2/libbystatement.p...
Doctors shirking their duty due to fear of persecution via prosecution: http://www.doctorgorrell.com/a-bad-time-to-be-a-chronic-pain...
Article about how the fear is causing doctors to resist adequate remedies: http://www.healthsearchonline.com/doctors-prescribing-pain-m...
The white house is calling it an "epidemic": http://www.whitehouse.gov/ondcp/