Kluge M, Schüssler P, Künzel HE, Dresler M, Yassouridis A, Steiger A. Increased nocturnal secretion of ACTH and cortisol in obsessive compulsive disorder. Journal of Psychiatric Research. 2007 Dec;41(11):928–33. doi: 10.1016/j.jpsychires.2006.08.005.