Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comment
. 2018 Dec 28;16(1):237.
doi: 10.1186/s12916-018-1228-y.

The SMILES trial: an important first step

Felice N Jacka  1   2   3 , Adrienne O'Neil  4   5 , Catherine Itsiopoulos  6 , Rachelle Opie  7 , Sue Cotton  8   9 , Mohammadreza Mohebbi  4   10 , David Castle  11   12 , Sarah Dash  4 , Cathrine Mihalopoulos  13 , Mary Lou Chatterton  13 , Laima Brazionis  6   14 , Olivia M Dean  4   11   15 , Allison Hodge  16   17 , Michael Berk  4   8   11   15
Affiliations
Comment

The SMILES trial: an important first step

Felice N Jacka et al. BMC Med. .

Abstract

The SMILES trial was the first intervention study to test dietary improvement as a treatment strategy for depression. Molendijk et al. propose that expectation bias and difficulties with blinding might account for the large effect size. While we acknowledge the issue of expectation bias in lifestyle intervention trials and indeed discuss this as a key limitation in our paper, we observed a strong correlation between dietary change and change in depression scores, which we argue is consistent with a causal effect and we believe unlikely to be an artefact of inadequate blinding. Since its publication, our results have been largely replicated and our recent economic evaluation of SMILES suggests that the benefits of our approach extend beyond depression. We argue that the SMILES trial should be considered an important, albeit preliminary, first step in the field of nutritional psychiatry research.

Keywords: Depression; Diet; Nutrition; Randomised controlled trial.

PubMed Disclaimer

Conflict of interest statement

Competing interests

The authors declare that they have no competing interests.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Comment on

References

    1. Molendijk M, Fried EI, van der Does W. The SMILES trial: do recruitment practices explain the remarkably large effect? BMC Med. 2018. 10.1186/s12916-018-1221-5. - PMC - PubMed
    1. Jacka FN, O’Neil A, Opie R, Itsiopoulos C, Cotton S, Mohebbi M, et al. A randomised controlled trial of dietary improvement for adults with major depression (the ‘SMILES’ trial). BMC Med. 2017;15:23. - PMC - PubMed
    1. Hertogh EM, Schuit AJ, Peeters PH, Monninkhof EM. Noncompliance in lifestyle intervention studies: the instrumental variable method provides insight into the bias. J Clin Epidemiol. 2010;63:900–906. doi: 10.1016/j.jclinepi.2009.10.007. - DOI - PubMed
    1. Jacka FN. Nutritional psychiatry: where to next? EBioMedicine. 2017;17:24–29. doi: 10.1016/j.ebiom.2017.02.020. - DOI - PMC - PubMed
    1. Parletta N, Zarnowiecki D, Cho J, Wilson A, Bogomolova S, Villani A, et al. A Mediterranean-style dietary intervention supplemented with fish oil improves diet quality and mental health in people with depression: a randomized controlled trial (HELFIMED). Nutr Neurosci. 2017. 10.1080/1028415X.2017.1411320. - PubMed

LinkOut - more resources