title: The impact of whole-of-diet interventions on depression and anxiety: a systematic review of randomised controlled trials.
abstract: OBJECTIVE
  Non-pharmacological approaches to the treatment of depression and anxiety are of increasing importance, with emerging evidence supporting a role for lifestyle factors in the development of these disorders. Observational evidence supports a relationship between habitual diet quality and depression. Less is known about the causative effects of diet on mental health outcomes. Therefore a systematic review was undertaken of randomised controlled trials of dietary interventions that used depression and/or anxiety outcomes and sought to identify characteristics of programme success.
  
  
  METHODS
  A systematic search of the Cochrane, MEDLINE, EMBASE, CINAHL, PubMed and PyscInfo databases was conducted for articles published between April 1971 and May 2014.
  
  
  RESULTS
  Of the 1274 articles identified, seventeen met eligibility criteria and were included. All reported depression outcomes and ten reported anxiety or total mood disturbance. Compared with a control condition, almost half (47%) of the studies observed significant effects on depression scores in favour of the treatment group. The remaining studies reported a null effect. Effective dietary interventions were based on a single delivery mode, employed a dietitian and were less likely to recommend reducing red meat intake, select leaner meat products or follow a low-cholesterol diet.
  
  
  CONCLUSIONS
  Although there was a high level of heterogeneity, we found some evidence for dietary interventions improving depression outcomes. However, as only one trial specifically investigated the impact of a dietary intervention in individuals with clinical depression, appropriately powered trials that examine the effects of dietary improvement on mental health outcomes in those with clinical disorders are required.
authors.affiliation: 1Department of Dietetics and Human Nutrition, Faculty of Health Sciences,La Trobe University,Melbourne,VIC 3086,Australia.
authors.forename: Rachelle S
authors.initials: RS
authors.lastname: Opie
authors.affiliation: 2IMPACT Strategic Research Centre,School of Medicine,Deakin University,Geelong,Victoria,Australia.
authors.forename: Adrienne
authors.initials: A
authors.lastname: O'Neil
authors.affiliation: 1Department of Dietetics and Human Nutrition, Faculty of Health Sciences,La Trobe University,Melbourne,VIC 3086,Australia.
authors.forename: Catherine
authors.initials: C
authors.lastname: Itsiopoulos
authors.affiliation: 2IMPACT Strategic Research Centre,School of Medicine,Deakin University,Geelong,Victoria,Australia.
authors.forename: Felice N
authors.initials: FN
authors.lastname: Jacka
mesh_terms: D001007:Anxiety / Q000178:diet therapy*; D001008:Anxiety Disorders / Q000178:diet therapy*; D003863:Depression / Q000178:diet therapy*; D003866:Depressive Disorder / Q000178:diet therapy*; D006801:Humans
keywords: Depression; Diet; Diet intervention; Mental health