Interesting commentary on ghostwriting:

“Ghostwriting occurs when someone makes substantial contributions to a manuscript without attribution or disclosure. It is considered bad publication practice in the medical sciences, and some argue it is scientific misconduct. This debate examines how best to tackle ghostwriting in the medical literature from the perspectives of a researcher, an editor, and the professional medical writer.”

What Should Be Done To Tackle Ghostwriting in the Medical Literature?
Gøtzsche PC, Kassirer JP, Woolley KL, Wager E, Jacobs A, et al.
PLoS Medicine Vol. 6, No. 2, e23 doi:10.1371/journal.pmed.1000023