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Trial registered on ANZCTR


Registration number
ACTRN12620000605998
Ethics application status
Approved
Date submitted
15/04/2020
Date registered
25/05/2020
Date last updated
25/05/2020
Date data sharing statement initially provided
25/05/2020
Date results information initially provided
25/05/2020
Type of registration
Retrospectively registered

Titles & IDs
Public title
Associations between diet quality and common mental disorders in emerging adults: results from a nationally representative sample
Scientific title
An analysis of associations between diet quality indicators and common mental disorders in a nationally representative sample of Australian emerging adults
Secondary ID [1] 300937 0
Nil
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Diet 316935 0
Mental Health 316936 0
Condition category
Condition code
Mental Health 315097 315097 0 0
Depression
Mental Health 315098 315098 0 0
Anxiety
Mental Health 315099 315099 0 0
Other mental health disorders
Public Health 315100 315100 0 0
Epidemiology
Diet and Nutrition 315160 315160 0 0
Other diet and nutrition disorders

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
Diet quality was measured via self reported proxies of healthy and unhealthy diet. Healthy and unhealthy diet proxies were average daily fruit and vegetable consumption and average weekly sugar sweetened beverage consumption, respectively. Each participant had a single observation at one time point for each exposure variable. Data are pre-existing from the Australian National Health Survey (NHS) 2017-18 and data collection occurred via face to face interviews over a 12-month period between 2 July 2017 and 30 June 2018. The Australian NHS 2017-18 does not require any further involvement by participants. All data for the current study is sourced from the Australian NHS 2017-18.
Intervention code [1] 317250 0
Early Detection / Screening
Comparator / control treatment
No control group
Control group
Uncontrolled

Outcomes
Primary outcome [1] 323422 0
Psychological distress: Psychological distress was measured by the Kessler Psychological Distress Scale-10 (K10), with total scores ranging 10 (low distress) to 50 (severe distress). K10 scores were categorised into low (10-15), moderate (16-21), high (22-29) and very high (30-50) distress levels, as based on prior research and recommended by the Australian Bureau of Statistics.
Timepoint [1] 323422 0
Mental health data was also from the Australian National Health Survey (NHS) 2017-28. Psychological distress was measured at a single time point during the Australian NHS 2017-18.
Primary outcome [2] 323654 0
Depression and related symptoms: Depression and related symptoms was measured by a single survey item asking participants to identify which, if any, mental conditions/symptoms they have from those listed on a prompt card (e.g. 'depression', 'feeling depressed').
Timepoint [2] 323654 0
Mental health data was also from the Australian National Health Survey (NHS) 2017-28. Depression and related symptoms was measured at a single time point during the Australian NHS 2017-18.
Primary outcome [3] 323655 0
Anxiety and related symptoms: Anxiety and related symptoms was measured by a single survey item asking participants to identify which, if any, mental conditions/symptoms they have from those listed on a prompt card (e.g. 'anxiety disorder', 'panic attacks', 'feeling anxious, nervous or tense').
Timepoint [3] 323655 0
Mental health data was also from the Australian National Health Survey (NHS) 2017-28. Anxiety and related symptoms was measured at a single time point during the Australian NHS 2017-18.
Secondary outcome [1] 381885 0
Co-morbid depression, anxiety and related symptoms: Co-morbid depression, anxiety and related symptoms is a composite secondary outcome. This was measured by combining self-reported data from a single survey item asking participants to identify which, if any, mental conditions they have from a list of conditions provided. Participants who reported the presence of an anxiety condition or symptoms AND the presence of a depressive condition or symptoms were combined to create a single group with co-morbid depression, anxiety and related symptoms.
Timepoint [1] 381885 0
Mental health data was also from the Australian National Health Survey (NHS) 2017-28. Co-morbid depression, anxiety and related symptoms was measured at a single time point during the Australian NHS 2017-18.

Eligibility
Key inclusion criteria
Participants had to be aged 18-29 years and have complete mental health and/or dietary data from the Australian National Health Survey 2017-18.
Minimum age
18 Years
Maximum age
29 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Other mental illness (i.e. disorders classified separately from depressive and anxiety disorders in the Diagnostic and Statistical Manual of Mental Disorders 5th Edition).

Study design
Purpose
Natural history
Duration
Cross-sectional
Selection
Random sample
Timing
Retrospective
Statistical methods / analysis
The data will be weighted prior to analyses to ensure data are representative of the in-scope Australian population. Differences in participant characteristics between outcome variables will be examined using t-tests (continuous variables) and the chi-square test (categorical variables). Statistical modelling will be guided by the use of Directed Acyclic Graphs. Regression models will be run for each outcome variable (psychological distress, conditions and related symptoms of depression, anxiety, and co-morbid depression and anxiety). Interaction effects will be analysed for key variables (e.g. sex) and models run separately for these variables if statistically indicated. Regression analyses will include models that are 1) unadjusted, 2) adjusted for demographic covariates (e.g. age, sex, SES, education, income) and 3) adjusted for demographic and lifestyle covariates (e.g. physical activity, smoking, alcohol consumption).

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
ACT,NSW,NT,QLD,SA,TAS,WA,VIC

Funding & Sponsors
Funding source category [1] 305380 0
Government body
Name [1] 305380 0
Australian Bureau of Statistics
Address [1] 305380 0
Level 3
818 Bourke Street
Docklands VIC
Australia 3008
Country [1] 305380 0
Australia
Primary sponsor type
University
Name
Deakin University
Address
Gheringhap Street
Geelong VIC
Australia 3220
Country
Australia
Secondary sponsor category [1] 305758 0
None
Name [1] 305758 0
Address [1] 305758 0
Country [1] 305758 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 305711 0
Deakin University Human Research Ethics Committee
Ethics committee address [1] 305711 0
221 Burwood Hwy
Burwood VIC
Australia 3125
Ethics committee country [1] 305711 0
Australia
Date submitted for ethics approval [1] 305711 0
Approval date [1] 305711 0
17/07/2019
Ethics approval number [1] 305711 0
2019-285

Summary
Brief summary
This study is a secondary analysis of cross-sectional, nationally representative data from the Australian National Health Survey 2017-18. Data will be obtained from the Australian Bureau of Statistics (ABS) in the form of a Confidentialised Unit Record File (CURF).
The aim of this study is to investigate the associations between indicators of diet quality as an exposure of interest, and common mental disorders as outcomes of interest, among a large, nationally representative cohort of emerging adults in Australia. It is hypothesised that 1) indicators of high healthy and low unhealthy diet will be independently associated with lower rates of common mental disorders, and 2) indicators of low healthy and high unhealthy diet will be independently associated with higher rates of common mental disorders.
Trial website
Trial related presentations / publications
Public notes
Ethics approval for the the data included in this study was previously obtained via the Australian Institute for Health and Welfare (AIHW). Informed consent was provided from all participants. Data will be accessed with permission of the data custodians and the data used in this study are pre-existing and de-identified.

Contacts
Principal investigator
Name 101314 0
Ms Sam Collins
Address 101314 0
Deakin University
1 Gheringhap St
Geelong VIC
Australia 3220
Country 101314 0
Australia
Phone 101314 0
+61 3 5227 1100
Fax 101314 0
Email 101314 0
collinssa@deakin.edu.au
Contact person for public queries
Name 101315 0
Ms Sam Collins
Address 101315 0
Deakin University
1 Gheringhap St
Geelong VIC
Australia 3220
Country 101315 0
Australia
Phone 101315 0
+61 3 5227 1100
Fax 101315 0
Email 101315 0
collinssa@deakin.edu.au
Contact person for scientific queries
Name 101316 0
Ms Sam Collins
Address 101316 0
Deakin University
1 Gheringhap St
Geelong VIC
Australia 3220
Country 101316 0
Australia
Phone 101316 0
+61 3 5227 1100
Fax 101316 0
Email 101316 0
collinssa@deakin.edu.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
Permission for sharing IPD lies with data custodians at the Australian Bureau of Statistics (ABS).
What supporting documents are/will be available?
No other documents available
Summary results
Have study results been published in a peer-reviewed journal?
No
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary