Subthreshold DepressionNCT07880652
Dietary Education Intervention for Subthreshold Depression (MIND-Trial)
A study testing Mediterranean-Style Dietary Education Program and Befriending in people with Subthreshold Depression, run by Institute of Mental Health, Singapore at 1 site in Singapore.
Trial summary
This randomized controlled trial evaluates the efficacy of an 8-week dietary education intervention in adults with subthreshold depression. Participants will be randomly assigned in a 1:1 ratio to either a dietary education intervention or a befriending control condition. Read more about this study
- Who is it for?
- Ages 21 to 60 years
- Conditions the study is for
- Subthreshold Depression
- What is being tested?
- Mediterranean-Style Dietary Education Program and Befriending
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 64 participants
- Where
- 1 siteSingapore
- Study dates
- Oct 2026to Dec 2028
- Phase
- Interventional
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 21 to 60 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Male or female, aged 21 to 60 years.
- Meets the operational diagnostic criteria for subthreshold depression.
- Has not been following a Mediterranean-style diet, based on self-report and a - Mediterranean Diet Adherence Screener (MEDAS) score ≤9.
- Able to converse in English.
- Able to use a computer or mobile device with internet access.
- Capable of providing informed consent.
Who cannot join
- Current use of antidepressants, antipsychotics, or mood stabilizers.
- Self-reported lifetime diagnosis of bipolar disorder, a psychotic disorder, an eating disorder, or a current substance use disorder.
- Major life trauma, such as recent bereavement or job loss, within the preceding 3 months.
- Current participation in an intervention targeting diet.
- Severe food allergies, intolerances, or aversions.
- Unwilling to accept a Mediterranean-style diet.
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- Current daily or regular use of over-the-counter or prescription probiotic/prebiotic supplements.
- Systemic oral or intravenous antibiotic use within 30 days before the study.
- Self-reported chronic gastrointestinal disorder, including inflammatory bowel disease, irritable bowel syndrome, or celiac disease.
- Self-reported history of significant gastrointestinal surgery, such as gastric bypass or bowel resection.
- Self-reported systemic autoimmune disease or active chronic infectious disease.
- Currently pregnant or lactating, or planning pregnancy during the study.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Singapore1 site
Institute of Mental Health
Singapore, 539747
Jiangbo Ying, 65+63892000, jiangbo.john.ying@nhghealth.com.sg
About this study
Official title: Microbiome in Depression: A Dietary Education Intervention Trial on the Microbiome and Subthreshold Depression (MIND-Trial)
This randomized controlled trial evaluates the efficacy of an 8-week dietary education intervention in adults with subthreshold depression. Participants will be randomly assigned in a 1:1 ratio to either a dietary education intervention or a befriending control condition. The dietary intervention consists of online dietary education and counseling designed to encourage a Mediterranean dietary pattern. The control group will receive online befriending sessions of similar frequency and duration. The study will evaluate changes in depressive symptoms and investigate changes in oral and gut microbiota, dietary measures, psychiatric symptoms, metabolic measures, and neurobiological markers.
Read the detailed description
Subthreshold depression is characterized by clinically significant depressive symptoms that do not meet the full diagnostic criteria for major depressive disorder and represents an important opportunity for early intervention.
Emerging evidence suggests that diet and the gut microbiome may be involved in mental health through the microbiota-gut-brain axis. However, evidence regarding dietary interventions specifically for individuals with subthreshold depression is limited, particularly in Asian populations, and the mechanisms linking dietary changes with depressive symptoms remain incompletely understood.
The MIND-Trial is an 8-week, parallel-group, open-label randomized controlled trial involving 64 adults with subthreshold depression. Participants will be randomized 1:1 to a dietary education intervention or a befriending control condition.
Participants assigned to the intervention will receive online dietary education and counseling every two weeks, incorporating tailored dietary recommendations and structured goal setting to encourage a Mediterranean dietary pattern. Participants assigned to the control condition will receive online befriending sessions at the same frequency and duration, involving conversations on neutral topics.
The study will evaluate depressive symptoms as well as dietary adherence, other psychiatric and gastrointestinal symptoms, anthropometric measures, oral and gut microbiota, metabolites, and neurobiological markers.
- Conditions
- Subthreshold Depression
- Being tested
- Mediterranean-Style Dietary Education Program, Befriending
- Keywords
- Subthreshold depression, Subclinical depression, Dietary intervention, Mediterranean diet, Gut microbiome, Oral microbiome, Nutritional psychiatry, Microbiota-gut-brain axis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Mediterranean-Style Dietary Education ProgramBehavioural
An 8-week online dietary education and counseling program delivered every two weeks, incorporating tailored dietary recommendations and structured goal setting to encourage adoption of a Mediterranean dietary pattern.
BefriendingBehavioural
Online befriending sessions delivered at the same frequency and duration as the dietary education intervention. Sessions consist of conversations on neutral topics intended to maintain engagement and control for nonspecific factors such as attention, treatment expectancy, and engagement.
| Study group | Role | What they receive |
|---|---|---|
| Dietary Education Intervention | Experimental | Participants will receive an online dietary education program delivered via Microsoft Teams by qualified dietitians or trained research staff every two weeks over an 8-week period. Sessions will incorporate internet-delivered dietary education, counseling, tailored dietary recommendations, and structured goal setting to encourage a Mediterranean dietary pattern. Participants will receive a S$25 grocery voucher and a list of Mediterranean foods every two weeks. Receives: Behavioral: Mediterranean-Style Dietary Education Program |
| Befriending Control | Active comparator | Participants will receive befriending sessions via Microsoft Teams at the same frequency and duration as the dietary education sessions. Researchers will engage participants in conversations on neutral topics such as hobbies, books, music, and sports. Participants will receive a S$25 grocery voucher every two weeks and will be advised to continue their usual grocery shopping habits. Receives: Behavioral: Befriending |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Depressive Symptoms Assessed by the Center for Epidemiologic Studies Depression Scale (CES-D)
Depressive symptoms will be assessed using the Center for Epidemiologic Studies Depression Scale (CES-D). The CES-D is a 20-item self-report measure with a total score ranging from 0 to 60. Higher scores indicate greater severity of depressive symptoms (i.e., a worse outcome). Change in CES-D score from baseline will be compared between the dietary education intervention and befriending control groups.
Measured: Baseline to Week 8
Secondary outcomes (5)
Change in Depressive Symptoms Assessed by the Patient Health Questionnaire-9 (PHQ-9)
Depressive symptoms will be assessed using the Patient Health Questionnaire-9 (PHQ-9). The PHQ-9 consists of 9 items and has a total score ranging from 0 to 27. Higher scores indicate greater severity of depressive symptoms (i.e., a worse outcome).
Measured: Baseline through Week 8
Change in Insomnia Symptoms Assessed by the Insomnia Severity Index (ISI)
Insomnia symptoms will be assessed using the Insomnia Severity Index (ISI). The ISI consists of 7 items and has a total score ranging from 0 to 28. Higher scores indicate greater severity of insomnia symptoms (i.e., a worse outcome).
Measured: Baseline through Week 8
Change in Anxiety Symptoms Assessed by the Beck Anxiety Inventory (BAI)
Anxiety symptoms will be assessed using the Beck Anxiety Inventory (BAI). The BAI consists of 21 items and has a total score ranging from 0 to 63. Higher scores indicate greater severity of anxiety symptoms (i.e., a worse outcome).
Measured: Baseline through Week 8
Change in Autistic Traits Assessed by the Autism-Spectrum Quotient (AQ)
Autistic traits will be assessed using the Autism-Spectrum Quotient (AQ). The AQ consists of 50 items and has a total score ranging from 0 to 50 using the standard binary scoring method. Higher scores indicate a greater level of autistic traits.
Measured: Baseline through Week 8
Change in Mediterranean Diet Adherence Assessed by the Mediterranean Diet Adherence Screener (MEDAS)
Adherence to a Mediterranean dietary pattern will be assessed using the Mediterranean Diet Adherence Screener (MEDAS). The MEDAS consists of 14 items and has a total score ranging from 0 to 14. Higher scores indicate greater adherence to a Mediterranean dietary pattern (i.e., a better outcome).
Measured: Baseline through Week 8
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Oct 2026
- Study startOct 2026 (estimated)
- Primary completionOct 2028 (estimated)
- Study completionDec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Subthreshold DepressionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 64 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Institute of Mental Health, Singapore
- Sponsor type
- University, hospital or other
- Collaborators
- Nanyang Technological University
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07880652
- Sponsor's protocol ID
- 2026-0119
- Status last verified
- Oct 2026
- First submitted
- 28 Sep 2026
- Last updated
- 19 Oct 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No