title: A randomised controlled trial of dietary improvement for adults with major depression (the 'SMILES' trial).
abstract: BACKGROUND
  The possible therapeutic impact of dietary changes on existing mental illness is largely unknown. Using a randomised controlled trial design, we aimed to investigate the efficacy of a dietary improvement program for the treatment of major depressive episodes.
  
  
  METHODS
  'SMILES' was a 12-week, parallel-group, single blind, randomised controlled trial of an adjunctive dietary intervention in the treatment of moderate to severe depression. The intervention consisted of seven individual nutritional consulting sessions delivered by a clinical dietician. The control condition comprised a social support protocol to the same visit schedule and length. Depression symptomatology was the primary endpoint, assessed using the Montgomery-Åsberg Depression Rating Scale (MADRS) at 12 weeks. Secondary outcomes included remission and change of symptoms, mood and anxiety. Analyses utilised a likelihood-based mixed-effects model repeated measures (MMRM) approach. The robustness of estimates was investigated through sensitivity analyses.
  
  
  RESULTS
  We assessed 166 individuals for eligibility, of whom 67 were enrolled (diet intervention, n = 33; control, n = 34). Of these, 55 were utilising some form of therapy: 21 were using psychotherapy and pharmacotherapy combined; 9 were using exclusively psychotherapy; and 25 were using only pharmacotherapy. There were 31 in the diet support group and 25 in the social support control group who had complete data at 12 weeks. The dietary support group demonstrated significantly greater improvement between baseline and 12 weeks on the MADRS than the social support control group, t(60.7) = 4.38, p < 0.001, Cohen's d = -1.16. Remission, defined as a MADRS score <10, was achieved for 32.3% (n = 10) and 8.0% (n = 2) of the intervention and control groups, respectively (χ2(1) = 4.84, p = 0.028); number needed to treat (NNT) based on remission scores was 4.1 (95% CI of NNT 2.3-27.8). A sensitivity analysis, testing departures from the missing at random (MAR) assumption for dropouts, indicated that the impact of the intervention was robust to violations of MAR assumptions.
  
  
  CONCLUSIONS
  These results indicate that dietary improvement may provide an efficacious and accessible treatment strategy for the management of this highly prevalent mental disorder, the benefits of which could extend to the management of common co-morbidities.
  
  
  BACKGROUND
  Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12612000251820 . Registered on 29 February 2012.
authors.affiliation: IMPACT Strategic Research Centre, Deakin University, Geelong, VIC, Australia. f.jacka@deakin.edu.au.|Department of Psychiatry, University of Melbourne, Melbourne, VIC, Australia. f.jacka@deakin.edu.au.|Centre for Adolescent Health, Murdoch Childrens Research Institute, Melbourne, VIC, Australia. f.jacka@deakin.edu.au.|Black Dog Institute, Randwick, NSW, Australia. f.jacka@deakin.edu.au.|Food & Mood Centre, Deakin University, IMPACT SRC, School of Medicine, PO Box 281, Geelong, 3220, Victoria, Australia. f.jacka@deakin.edu.au.
authors.forename: Felice N
authors.initials: FN
authors.lastname: Jacka
authors.affiliation: IMPACT Strategic Research Centre, Deakin University, Geelong, VIC, Australia.|School of Population Health, The University of Melbourne, Melbourne, VIC, Australia.|Food & Mood Centre, Deakin University, IMPACT SRC, School of Medicine, PO Box 281, Geelong, 3220, Victoria, Australia.
authors.forename: Adrienne
authors.initials: A
authors.lastname: O'Neil
authors.affiliation: School of Allied Health, La Trobe University, Melbourne, VIC, Australia.|Food & Mood Centre, Deakin University, IMPACT SRC, School of Medicine, PO Box 281, Geelong, 3220, Victoria, Australia.
authors.forename: Rachelle
authors.initials: R
authors.lastname: Opie
authors.affiliation: School of Allied Health, La Trobe University, Melbourne, VIC, Australia.
authors.forename: Catherine
authors.initials: C
authors.lastname: Itsiopoulos
authors.affiliation: Orygen, The National Centre of Excellence in Youth Mental Health, Parkville, VIC, Australia.
authors.forename: Sue
authors.initials: S
authors.lastname: Cotton
authors.affiliation: IMPACT Strategic Research Centre, Deakin University, Geelong, VIC, Australia.
authors.forename: Mohammedreza
authors.initials: M
authors.lastname: Mohebbi
authors.affiliation: Department of Psychiatry, University of Melbourne, Melbourne, VIC, Australia.|St Vincents Hospital, Fitzroy, VIC, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Castle
authors.affiliation: IMPACT Strategic Research Centre, Deakin University, Geelong, VIC, Australia.|Food & Mood Centre, Deakin University, IMPACT SRC, School of Medicine, PO Box 281, Geelong, 3220, Victoria, Australia.
authors.forename: Sarah
authors.initials: S
authors.lastname: Dash
authors.affiliation: Centre for Population Health Research, Deakin University, Geelong, VIC, Australia.
authors.forename: Cathrine
authors.initials: C
authors.lastname: Mihalopoulos
authors.affiliation: Centre for Population Health Research, Deakin University, Geelong, VIC, Australia.
authors.forename: Mary Lou
authors.initials: ML
authors.lastname: Chatterton
authors.affiliation: School of Allied Health, La Trobe University, Melbourne, VIC, Australia.|Department of Medicine, The University of Melbourne, Melbourne, VIC, Australia.
authors.forename: Laima
authors.initials: L
authors.lastname: Brazionis
authors.affiliation: IMPACT Strategic Research Centre, Deakin University, Geelong, VIC, Australia.|Department of Psychiatry, University of Melbourne, Melbourne, VIC, Australia.|The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia.|Food & Mood Centre, Deakin University, IMPACT SRC, School of Medicine, PO Box 281, Geelong, 3220, Victoria, Australia.
authors.forename: Olivia M
authors.initials: OM
authors.lastname: Dean
authors.affiliation: Cancer Epidemiology and Intelligence Division, Cancer Council Victoria, Carlton, VIC, Australia.
authors.forename: Allison M
authors.initials: AM
authors.lastname: Hodge
authors.affiliation: IMPACT Strategic Research Centre, Deakin University, Geelong, VIC, Australia.|Orygen, The National Centre of Excellence in Youth Mental Health, Parkville, VIC, Australia.|The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia.|Food & Mood Centre, Deakin University, IMPACT SRC, School of Medicine, PO Box 281, Geelong, 3220, Victoria, Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Berk
mesh_terms: D000328:Adult; D001315:Australia; D015897:Comorbidity; D003865:Major Depressive Disorder / Q000150:complications / Q000178:diet therapy*; D005260:Female; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D008875:Middle Aged; D009520:New Zealand; D016037:Single-Blind Method; D016896:Treatment Outcome
keywords: Depression; Diet; Dietetics; Major depressive disorder; Nutrition; Randomised controlled trial