MDD is a common, recurrent, and frequently chronic disorder that is a leading contributor to functional impairment and disability (Murray and Lopez 1996).
Treatment is often challenging: an estimated 20% -40% of patients do not benefits sufficiently from existing antidepressant intervention including trials of medication and psychotherapy (Greden 2001)
16.1 million US adults with MDD
7.2 million treated
4.5 million poorly served
Nearly two thirds of patients do not benefits from initial pharmacotherapy (antidepressant treatment) and remain symptomatic and functional impaired. Sackeim HA, J Clinical psychiatry 2001, Rush AJ, Biol Psychiatry 2003)
Likelihood of achieving remission diminishes with each successive treatment attempt, as verified in Sequenced Treatment Alternatives to relived depression (STAR*D) study Trivedi et al Am J Psychiatry 2006