Depressive SympotomsSIC-EEG-NFNCT07815457
Real-Time EEG Neurofeedback Using a Subject-Independent Classifier in Women With Depressive Symptoms
A study testing Contingent Subject-Independent Classifier-Based EEG Neurofeedback in people with Depressive Sympotoms, run by Pontificia Universidad Catolica de Chile at 1 site in Chile.
Trial summary
This completed feasibility study examined whether right-handed women aged 18-35 years with mild-to-moderate depressive symptoms could use real-time electroencephalography (EEG) neurofeedback based on a subject-independent classifier to regulate brain activity toward a classifier-defined reference pattern. Read more about this study
- Who is it for?
- Ages 18 to 35 years, women only
- Conditions the study is for
- Depressive Sympotoms
- What is being tested?
- Contingent Subject-Independent Classifier-Based EEG Neurofeedback
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 20 participants
- Where
- 1 siteChile
- Study dates
- 4 Jan 2019to 30 Jan 2023
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 18 to 35 years
- Women only
- No healthy volunteers
- Adult
Who may be able to join
- Self-identification as a woman.
- Female sex assigned at birth, reported during the intake interview
- Self-reported right-handedness
- Age 18-35 years
- Beck Depression Inventory-II score of 14-29
- Hamilton Depression Rating Scale score below 24
- Score below 2 on the suicide-related item of both the Beck Depression
- Inventory-II and Hamilton Depression Rating Scale
Who cannot join
- Current psychotherapy
- Self-reported history of bipolar disorder or schizophrenia
- Prior suicide attempt
- Self-reported history of post-traumatic stress disorder, obsessive-compulsive disorder, substance use disorder, or anorexia nervosa
- Neurological disorder, including dementia, brain tumor, or epilepsy
- Intellectual disability
- Regular or intermittent use of benzodiazepines, anticonvulsants, or psychostimulants
- Use of another psychotropic medication unless the medication and dose had remained unchanged for at least 3 months before enrollment
Trial locations and contacts
1 site in 1 country.
Chile1 site
Laboratory for Brain-Machine Interfaces and Neuromodulation, Pontificia Universidad Católica de Chile
Santiago, RM, 8320000
About this study
Official title: A Randomized, Double-blind Feasibility Study of a Subject-independent Classifier-based EEG Neurofeedback in Women With Depressive Symptoms
This completed feasibility study examined whether right-handed women aged 18-35 years with mild-to-moderate depressive symptoms could use real-time electroencephalography (EEG) neurofeedback based on a subject-independent classifier to regulate brain activity toward a classifier-defined reference pattern. Participants were randomly assigned to receive either classifier-contingent visual feedback with performance-contingent monetary rewards or noncontingent sham visual feedback with yoked monetary rewards. All participants completed five training sessions over approximately 3 weeks. The primary purpose was to determine whether overall classifier accuracy during training exceeded the theoretical 50% chance level. Changes in clinician-rated and self-reported depressive symptoms, associations between classifier performance and symptom change, EEG spatial patterns, and procedural tolerability were exploratory.
Read the detailed description
The subject-independent classifier had been developed from EEG recordings obtained from an independent reference sample of healthy right-handed women during positive autobiographical memory recall and motor imagery. It used a Filter Bank Common Spatial Pattern feature-extraction pipeline and a linear support vector machine to classify the two mental states from 28 EEG channels.
After eligibility and baseline assessments, participants were randomly assigned in a 1:1 ratio to an experimental or control arm using a sequence generated before the intervention. Participants and the clinical psychologists administering the Hamilton Depression Rating Scale were masked to allocation. The experimental arm was implemented before the control arm because the control rewards were yoked to a reward sequence generated in the experimental arm; this operational sequence did not determine assignment.
Each participant completed five EEG neurofeedback sessions on separate days over approximately 3 weeks. Each session contained four 300-second runs. In each run, participants completed positive autobiographical memory recall and motor imagery blocks while viewing a thermometer-like display. In the experimental arm, the display was updated approximately once per second according to the classifier output and monetary rewards depended on run-level classifier accuracy. In the control arm, display movements were random and independent of EEG activity, and rewards were yoked to the run-by-run reward sequence of the experimental participant with the highest total reward.
This record was created retrospectively after study completion. The protocol information reflects the completed study procedures and the outcome hierarchy reported in the final manuscript; exploratory analyses have not been promoted to primary outcomes.
- Conditions
- Depressive Sympotoms
- Being tested
- Contingent Subject-Independent Classifier-Based EEG Neurofeedback, Noncontingent Sham EEG Feedback With Yoked Rewards
- Keywords
- Brain-Computer Interface, Support Vector Machine, Brain Self-Regulation, Neuromodulation, EEG-Neurofeedback, neurofeedback
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Contingent Subject-Independent Classifier-Based EEG NeurofeedbackBehavioural
Five sessions were delivered on separate days over approximately 3 weeks. Each session comprised four 300-second runs separated by 1-3-minute rest intervals. Each run contained four 20-second positive autobiographical memory recall blocks and four 20-second motor imagery blocks. A pretrained Filter Bank Common Spatial Pattern-linear support vector machine classifier processed 28 EEG channels in real time. The visual thermometer rose or fell by one level according to whether each classifier output matched the instructed mental state. At the end of each run, participants viewed classifier accuracy and received a prespecified performance-contingent monetary reward.
Noncontingent Sham EEG Feedback With Yoked RewardsBehavioural
Participants received the same five-session schedule, task structure, visual display, and scripted instructions as the experimental arm. Each thermometer update was a randomly determined one-level increase or decrease and was independent of EEG activity. Rewards followed the run-by-run sequence obtained by the experimental-arm participant with the highest total reward and were not contingent on the control participant's classifier performance.
| Study group | Role | What they receive |
|---|---|---|
| Contingent SIC-Based EEG Neurofeedback | Experimental | Participants completed five EEG neurofeedback sessions over approximately 3 weeks. During positive autobiographical memory recall and motor imagery blocks, a thermometer-like display was updated approximately once per second according to the real-time output of a pretrained subject-independent classifier. Participants received run-level classifier accuracy feedback and performance-contingent monetary rewards. Receives: Behavioral: Contingent Subject-Independent Classifier-Based EEG Neurofeedback |
| Noncontingent Sham EEG Feedback | Sham comparator | Participants completed the same five-session schedule, mental tasks, scripted instructions, and thermometer display. Display movements were randomly generated and independent of EEG activity and classifier output. Monetary rewards were yoked to the run-by-run reward sequence of the experimental-arm participant with the highest total reward, and participants were not informed that rewards were unrelated to their own classifier performance. Receives: Behavioral: Noncontingent Sham EEG Feedback With Yoked Rewards |
What is being measured
The primary outcome is the main question the study is designed to answer.
Mean Overall Classifier Accuracy Across Five EEG Neurofeedback Sessions
Classifier accuracy was the percentage of classifier outputs during regulation blocks that matched the instructed mental state. Each run contained 160 classifier outputs during regulation periods. Run-level accuracy was averaged across four runs to obtain a session-level value, and session-level accuracy was averaged across five sessions for each participant. Overall accuracy was compared with the theoretical 50% chance level within each arm and between arms.
Measured: Across five training sessions over approximately 3 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Sep 2026
- Study start4 Jan 2019
- Primary completion23 Jan 2023
- Study completion30 Jan 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Depressive SympotomsStudies 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
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Two parallel arms with 1:1 randomized allocation. The experimental arm was implemented before the control arm only to generate the yoked reward schedule; the implementation order did not determine assignment.
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 20 participants (actual)
Sponsor and investigators
- Lead sponsor
- Pontificia Universidad Catolica de Chile
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Sergio M Ruiz, MD, PhD, Principal investigator, Department of Psychiatry, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, ChileRanganatha Sitaram, ME, PhD, Study chair, Department of Radiology, St. Jude Children's Research Hospital, Memphis (TN), USA.Jaime A Pereira, MD, PhD, Study director, Department of Psychiatry, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07815457
- Sponsor's protocol ID
- 160825011
- Other IDs
- 1211510, CIN250068, 160825011
- Acronym
- SIC-EEG-NF
- Status last verified
- Aug 2026
- First submitted
- 31 Aug 2026
- Last updated
- 11 Sep 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: The feasibility of sharing de-identified individual participant data and a data dictionary is under review. Any sharing plan will depend on participant consent, ethics and institutional approval, the ability to minimize re-identification risk in this small sample, and an appropriate data-use agreement.
Study at a glance
From the registry record, last updated by the sponsor on 11 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Randomized, Double-blind Feasibility Study of a Subject-independent Classifier-based EEG Neurofeedback in Women With Depressive Symptoms
- ClinicalTrials.gov ID
- NCT07815457
- Acronym / sponsor ID
- SIC-EEG-NF / 160825011
- Conditions
- Depressive Sympotoms
- Keywords
- Brain-Computer Interface, Support Vector Machine, Brain Self-Regulation, Neuromodulation, EEG-Neurofeedback, neurofeedback
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 20 participants (actual)
- Lead sponsor
- Pontificia Universidad Catolica de ChileUniversity, hospital or other
- Study start
- 4 Jan 2019 (actual)
- Primary completion
- 23 Jan 2023 (actual)
- Study completion
- 30 Jan 2023 (actual)
- First posted
- 11 Sep 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This completed feasibility study examined whether right-handed women aged 18-35 years with mild-to-moderate depressive symptoms could use real-time electroencephalography (EEG) neurofeedback based on a subject-independent classifier to regulate brain activity toward a classifier-defined reference pattern. Participants were randomly assigned to receive either classifier-contingent visual feedback with performance-contingent monetary rewards or noncontingent sham visual feedback with yoked monetary rewards. All participants completed five training sessions over approximately 3 weeks. The primary purpose was to determine whether overall classifier accuracy during training exceeded the theoretical 50% chance level. Changes in clinician-rated and self-reported depressive symptoms, associations between classifier performance and symptom change, EEG spatial patterns, and procedural tolerability were exploratory.
Detailed description
The subject-independent classifier had been developed from EEG recordings obtained from an independent reference sample of healthy right-handed women during positive autobiographical memory recall and motor imagery. It used a Filter Bank Common Spatial Pattern feature-extraction pipeline and a linear support vector machine to classify the two mental states from 28 EEG channels.
After eligibility and baseline assessments, participants were randomly assigned in a 1:1 ratio to an experimental or control arm using a sequence generated before the intervention. Participants and the clinical psychologists administering the Hamilton Depression Rating Scale were masked to allocation. The experimental arm was implemented before the control arm because the control rewards were yoked to a reward sequence generated in the experimental arm; this operational sequence did not determine assignment.
Each participant completed five EEG neurofeedback sessions on separate days over approximately 3 weeks. Each session contained four 300-second runs. In each run, participants completed positive autobiographical memory recall and motor imagery blocks while viewing a thermometer-like display. In the experimental arm, the display was updated approximately once per second according to the classifier output and monetary rewards depended on run-level classifier accuracy. In the control arm, display movements were random and independent of EEG activity, and rewards were yoked to the run-by-run reward sequence of the experimental participant with the highest total reward.
This record was created retrospectively after study completion. The protocol information reflects the completed study procedures and the outcome hierarchy reported in the final manuscript; exploratory analyses have not been promoted to primary outcomes.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
- Model description
- Two parallel arms with 1:1 randomized allocation. The experimental arm was implemented before the control arm only to generate the yoked reward schedule; the implementation order did not determine assignment.
| Arm | Type | Receives |
|---|---|---|
| Contingent SIC-Based EEG Neurofeedback | Experimental | Behavioral: Contingent Subject-Independent Classifier-Based EEG NeurofeedbackParticipants completed five EEG neurofeedback sessions over approximately 3 weeks. During positive autobiographical memory recall and motor imagery blocks, a thermometer-like display was updated approximately once per second according to the real-time output of a pretrained subject-independent classifier. Participants received run-level classifier accuracy feedback and performance-contingent monetary rewards. |
| Noncontingent Sham EEG Feedback | Sham comparator | Behavioral: Noncontingent Sham EEG Feedback With Yoked RewardsParticipants completed the same five-session schedule, mental tasks, scripted instructions, and thermometer display. Display movements were randomly generated and independent of EEG activity and classifier output. Monetary rewards were yoked to the run-by-run reward sequence of the experimental-arm participant with the highest total reward, and participants were not informed that rewards were unrelated to their own classifier performance. |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (8 listed)
- Self-identification as a woman.
- Female sex assigned at birth, reported during the intake interview
- Self-reported right-handedness
- Age 18-35 years
- Beck Depression Inventory-II score of 14-29
Key exclusion criteria (8 listed)
- Current psychotherapy
- Self-reported history of bipolar disorder or schizophrenia
- Prior suicide attempt
- Self-reported history of post-traumatic stress disorder, obsessive-compulsive disorder, substance use disorder, or anorexia nervosa
- Neurological disorder, including dementia, brain tumor, or epilepsy
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Contingent Subject-Independent Classifier-Based EEG NeurofeedbackFive sessions were delivered on separate days over approximately 3 weeks. Each session comprised four 300-second runs separated by 1-3-minute rest intervals. Each run contained four 20-second positive autobiographical memory recall blocks and four 20-second motor imagery blocks. A pretrained Filter Bank Common Spatial Pattern-linear support vector machine classifier processed 28 EEG channels in real time. The visual thermometer rose or fell by one level according to whether each classifier output matched the instructed mental state. At the end of each run, participants viewed classifier accuracy and received a prespecified performance-contingent monetary reward. | Behavioural | Contingent SIC-Based EEG Neurofeedback |
| Noncontingent Sham EEG Feedback With Yoked RewardsParticipants received the same five-session schedule, task structure, visual display, and scripted instructions as the experimental arm. Each thermometer update was a randomly determined one-level increase or decrease and was independent of EEG activity. Rewards followed the run-by-run sequence obtained by the experimental-arm participant with the highest total reward and were not contingent on the control participant's classifier performance. | Behavioural | Noncontingent Sham EEG Feedback |
Primary outcome
Mean Overall Classifier Accuracy Across Five EEG Neurofeedback Sessions
Time frame: Across five training sessions over approximately 3 weeks
Classifier accuracy was the percentage of classifier outputs during regulation blocks that matched the instructed mental state. Each run contained 160 classifier outputs during regulation periods. Run-level accuracy was averaged across four runs to obtain a session-level value, and session-level accuracy was averaged across five sessions for each participant. Overall accuracy was compared with the theoretical 50% chance level within each arm and between arms.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Sep 2026.
- Individual participant dataSharing planned: Undecided. The feasibility of sharing de-identified individual participant data and a data dictionary is under review. Any sharing plan will depend on participant consent, ethics and institutional approval, the ability to minimize re-identification risk in this small sample, and an appropriate data-use agreement.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Sergio M Ruiz, MD, PhD principal investigator
Department of Psychiatry, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
Ranganatha Sitaram, ME, PhD study chair
Department of Radiology, St. Jude Children's Research Hospital, Memphis (TN), USA.
Jaime A Pereira, MD, PhD study director
Department of Psychiatry, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Contingent Subject-Independent Classifier-Based EEG Neurofeedback in people with Depressive Sympotoms, run by Pontificia Universidad Catolica de Chile at 1 site in Chile.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 11 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Chile. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Mean Overall Classifier Accuracy Across Five EEG Neurofeedback Sessions (time frame: Across five training sessions over approximately 3 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Sep 2026.