title: Treatment response for acute depression is not associated with number of previous episodes: lack of evidence for a clinical staging model for major depressive disorder.
abstract: Mental illness has been observed to follow a neuroprogressive course, commencing with prodrome, then onset, recurrence and finally chronic illness. In bipolar disorder and schizophrenia responsiveness to treatment mirrors these stages of illness progression, with greater response to treatment in the earlier stages of illness and greater treatment resistance in chronic late stage illness. Using data from 5627 participants in 15 controlled trials of duloxetine, comparator arm (paroxetine, venlafaxine, escitalopram) or placebo for the treatment of an acute depressive episode, the relationship between treatment response and number of previous depressive episodes was determined. Data was dichotomised for comparisons between participants who had >3 previous episodes (n=1697) or ≤3 previous episodes (n=3930), and additionally for no previous episodes (n=1381) or at least one previous episode (n=4246). Analyses were conducted by study arm for each clinical trial, and results were then pooled. There was no significant difference between treatment response and number of previous depressive episodes. This unexpected finding suggests that treatments to reduce symptoms of depression during acute illness do not lose efficacy for patients with a longer history of illness.
authors.affiliation: Department of Psychiatry, University of Melbourne, Parkville, VIC, Australia. Seetald@barwonhealth.org.au
authors.forename: Seetal
authors.initials: S
authors.lastname: Dodd
authors.forename: Michael
authors.initials: M
authors.lastname: Berk
authors.forename: Katarina
authors.initials: K
authors.lastname: Kelin
authors.forename: Michele
authors.initials: M
authors.lastname: Mancini
authors.forename: Alexander
authors.initials: A
authors.lastname: Schacht
mesh_terms: D000208:Acute Disease; D000328:Adult; D000928:Antidepressive Agents / Q000627:therapeutic use*; D015283:Citalopram / Q000627:therapeutic use; D003511:Cyclohexanols / Q000627:therapeutic use; D003863:Depression / Q000523:psychology; D003865:Major Depressive Disorder / Q000188:drug therapy* / Q000523:psychology; D000068736:Duloxetine Hydrochloride; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017374:Paroxetine / Q000627:therapeutic use; D012008:Recurrence; D013876:Thiophenes; D013997:Time Factors; D016896:Treatment Outcome; D000069470:Venlafaxine Hydrochloride
chemical_list: D000928:Antidepressive Agents; D003511:Cyclohexanols; D013876:Thiophenes; D015283:Citalopram; D017374:Paroxetine; D000069470:Venlafaxine Hydrochloride; D000068736:Duloxetine Hydrochloride
keywords: Antidepressant; Depression; Meta-analysis; Staging; Treatment