An interventional study of Ecologic® Barrier and Placebo powder in Mild-to-moderate Depression, Neural Activity and Executive Function (Cognition), sponsored by University of Reading. Not yet recruiting at 1 site in United Kingdom. Open to participants aged 25 Years to 40 Years. Per ClinicalTrials.gov, last updated 2026-06-25.
Sponsored by University of Reading · Not applicable, Interventional, and Treatment
This study aims to investigate the acute and chronic effects of 16-week probiotic supplementation (Ecologic® Barrier) on depressive symptoms and neural activity in those with mild-to-moderate depression.
This study will use a randomised, double-blind, placebo-controlled design. A total of 76 participants will be recruited and will receive either one sachet of the probiotic (Ecologic® Barrier) or one sachet of a placebo, matched in taste, smell, appearance, and packaging. Outcomes will be measured at baseline, 24 hours, and at 16 weeks for all participants. These include measures of general mood, depressive symptoms, executive function, and neural activity. Neural activation will be measured using electroencephalography (EEG), specifically measuring the P300 event-related potential (ERP) during an n-back task. In addition to the n-back task, executive function, specifically working memory and cognitive flexibility will be tested using the task-switching task.
The main question this study aims to answer is:
8,577 studies on the registry are indexed under Depression; 1,720 are open to participants now.
This study's planned enrollment of 76 is close to the median of 81 across 7,063 interventional studies indexed under Depression.
Browse Depression studies →University of Reading is the lead sponsor of 150 studies on the registry; 21 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Participants will consume one sachet of Ecologic® Barrier powder(1x10\^10 CFU/day), mixed in warm water with a meal. The sachets can be stored at room temperature.
Dietary Supplement: Ecologic® Barrier
A placebo matched for packaging, visual appearance, smell, and taste will be given. Similar to the instructions on how to take the probiotic, subjects will consume one sachet per day, kept at room temperature, mixed into warm water with a meal.
Dietary Supplement: Placebo powder
Ecologic® Barrier (1x1010 CFU/day).
Also known as: Probiotics
Matched placebo
Also known as: placebo
Leiden Index of Depression Sensitivity - Revised (LEIDS-R) vulnerability/sensitivity for depression.
A standardised measure of cognitive reactivity. This questionnaire consists of 34 items, in which participants rate on a scale from 0 to 4, how strongly they feel each statement relates to them when they feel somewhat sad.
Time frame: Baseline and 16 weeks
Leiden Index of Depression Sensitivity - Revised (LEIDS-R). The following subscales are of interest: rumination, hopelessness/suicidality, acceptance/coping, aggression, control, and risk aversion.
A standardised measure of cognitive reactivity. This questionnaire consists of 34 items, in which participants rate on a scale from 0 to 4, how strongly they feel each statement relates to them when they feel somewhat sad.
Time frame: Baseline, 24 hours, and 16 weeks
Beck Depression Inventory (BDI-II)
A robust tool consisting of 21 items used to measure the severity of depression. It focuses on symptoms experienced in the last 2 weeks, such as cognitive and affective symptoms.
Time frame: Screening, baseline, 24 hours, and 16 weeks
Mini-International Neuropsychiatric Interview (MINI)
A short diagnostic interview designed to screen for 17 psychiatric disorders and the risk of suicide.
Time frame: Baseline, 24 hours, and 16 weeks
Rumination Response Scale (RRS)
A self-report questionnaire measuring the tendency to focus on negative thinking, distressing symptoms, and their causes when people feel down, sad, or depressed.
Time frame: Baseline, 24 hours, and 16 weeks
Neural Activity
P300 event-related potential (ERP) amplitude and latency during the n-back task. Resting-state and active-state alpha and theta power oscillations. An exploratory measure of the N2 ERP may be analysed alongside the P300.
Time frame: baseline, 24 hours, and 16 weeks
Task-switching Task
This is a measure of executive function and sustained attention. Participants will be shown a circle with 8 equally spaced radii, 2 of which form a bold bisecting line. Numbers are chosen randomly from a set of 1-4 \& 6-9 and displayed sequentially in a clockwise direction. A response of higher or lower than 5 is made for trials below the line, and a response of even or odd for numbers above the line. Accuracy and reaction time (RT) on correct trials, as well as accuracy and RT on trials where there is a 'switch cost' from stimuli moving from below to above the bold line and vice versa, are the main outcome measures.
Time frame: Baseline, 24 hours, and 16 weeks
N-back task
This is an executive function and working memory task. There are varying difficulties of this task, but this trial will use the 0-back and 2-back versions. The 0-back task involves participants being shown a sequence of letters and having to respond when the current letter matches that of the previous letter. In the 2-back task, participants will have to respond when the current letter matches the letter from two trials ago.
Time frame: baseline, 24 hours, and 16 weeks
Profile of Mood States short form (POMS-SF)
This is a condensed self-report questionnaire used to measure changes in mood, assessed across 6 sub-scales (tension-anxiety, depression-dejection, anger-hostility, vigour-activity, fatigue-inertia, and confusion-bewilderment) with 40 total items. A total mood disturbance score is provided.
Time frame: Baseline, 24 hours, and 16 weeks
Visual Analogue Scale (VAS) of Positive and Negative feelings
Visual Analogue Scale of positive/negative feelings via a daily assessment. This includes two questions asking participants to rate on a scale from 0 to 100 the extent to which they felt positive or negative feelings.
Time frame: Every day from baseline to the final 16-week time point.
Quality of Life (SF12)
The Quality of Life (SF12) is a questionnaire which asks for participants' views about their health. This information keeps track of how they feel and how well they can do their usual activities.
Time frame: Baseline, 24 hours, and 16 weeks
Gastrointestinal Symptom Rating Scale (GSRS)
This is a 15-item self-reported questionnaire assessing the severity of gastrointestinal symptoms. It uses a 7-point Likert scale, covering five symptom domains: reflux, abdominal pain, indigestion, diarrhoea, and constipation symptoms.
Time frame: Baseline, 24 hours, and 16 weeks
Generalised Anxiety Disorder-7 (GAD-7)
This is a self-report questionnaire used to measure the severity of generalised anxiety disorder. It has seven items and asks individuals to rate the frequency of anxiety symptoms over the past two weeks, with scores ranging from 0 to 21 to determine anxiety levels. Baseline scores may be used as a covariate.
Time frame: Baseline
Menstrual Cycle Data
Information regarding the first day of the most recent menstruation, regularity and contraception will be recorded. It is not a direct outcome measure, but data may be used as a covariate.
Time frame: Baseline and 16 weeks
Epic-Norfolk Food Frequency Questionnaire (FFQ)
This is a validated tool for analysing the average habitual dietary intake of micro and macronutrients of an individual in the UK, which is particularly important to explore in order to understand how the probiotic supplement may interact with diet and gut microbiome diversity. Data will be processed using the FETA software.
Time frame: Baseline and 16 weeks
Plan to share: No
No publications or documents are linked to this record.
Start is estimated for Jul 2026; primary completion for Mar 2027, 8 months later.
Of 3,468 non-industry interventional studies with no phase under Depression, half reached primary completion within 21 months of starting (the median), counting those still running; a quarter within 10 and three quarters within 41. This study's planned 8 months is below that.
Counting every sponsor, half of 3,566 studies reached it within 21 months; a quarter within 9 and three quarters within 41.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in Jun 2026. You cannot join it, but the record below documents what was studied.
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