The Leuven Longitudinal Late-Life Depression Study (L4D)

August 14, 2026 updated by: Universitaire Ziekenhuizen KU Leuven

The goal of this observational study is to learn about the long-term effects of late-life depression (LLD) in adults aged 60 and older. LLD is depression that begins for the first time later in life. Patients with this condition may feel sad for a long time or lose interest in activities they used to enjoy. They may also have problems with sleep, energy, or concentration. In some patients, this depression comes with changes in thinking and memory, which may be linked to a higher risk of dementia.

The investigators believe that changes in the brain play a role in this condition. The main questions this study aims to answer are:

Do patients with late-life depression have a higher risk of memory decline, dementia, return of depression, hospital stays, or death compared to healthy people? Can brain scans and blood tests help predict how the illness will develop over time?

The investigators will compare patients with late-life depression to healthy people of the same age and sex. This will help clarify how the illness develops over several years.

This is a follow-up study, which means no new treatment is being tested. The investigators will recruit participants from previous studies, drawn from two cohorts with a mean follow-up time since inclusion of 12 years and 6 years. The investigators collect information about health, memory, and mood, and compare it with earlier measurements. To do this, the investigators use existing information from past studies, medical records, brain scans, and blood samples.

Participants can take part if they:

Are at least 60 years old Took part in one of the earlier studies Give written permission to join

Participants may be asked to:

Have a conversation and take memory tests Give a blood sample Have a brain scan

These tests can take place in the hospital or at the participant's home. If a participant does not want to do the tests again, the investigators can ask their family doctor for important health information, with the participant's permission.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Enrolling by invitation

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
178

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Belgium
    • Flanders
      • Leuven, Flanders, Belgium, 3000
        • UZ Leuven

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Older Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

Participants are adults aged 60 years and older who took part in one of the earlier related studies. This group includes people diagnosed with late-life depression as well as healthy adults of the same age and sex who serve as a comparison group.

Participants are recruited from the existing cohort of these earlier studies, using their prior study data, medical records, brain scans, and blood samples. Participants will be asked to return for follow-up assessments, which can take place in the hospital or at their home.

Description

Inclusion Criteria:

  • Voluntary written informed consent of the participant or their legally authorized representative has been obtained prior to any screening procedures.
  • At least 18 years of age at the time of signing the Informed Consent Form (ICF).
  • Participants were included in the previous studies.

Exclusion Criteria:

  • Not applicable, since participants who met any exclusion criteria were already excluded from the previous studies.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Healthy controls
Late-life depression group
Same interventions in both groups

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Number of Participants Who Died
Time Frame: From enrollment in the initial cross-sectional study until date of death from any cause, assessed up to 12 years for cohort 1 and up to 6 years for cohort 2.
From enrollment in the initial cross-sectional study until date of death from any cause, assessed up to 12 years for cohort 1 and up to 6 years for cohort 2.
Number of Participants with Dementia
Time Frame: From enrollment in the initial cross-sectional study to the follow-up assessment, an average of 12 years for cohort 1 and 6 years for cohort 2
Participants with a MMSE score lower or equal to 10, and a CDR scale score higher or equal to 2, will be classified as having dementia.
From enrollment in the initial cross-sectional study to the follow-up assessment, an average of 12 years for cohort 1 and 6 years for cohort 2

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Rate of depressive episodes
Time Frame: From enrollment in the initial cross-sectional study to the follow-up assessment, an average of 12 years for cohort 1 and 6 years for cohort 2. If deceased, up until passing away.
Hospitalisations for depression, referrals to psychotherapy or psychiatry, suicide attempts
From enrollment in the initial cross-sectional study to the follow-up assessment, an average of 12 years for cohort 1 and 6 years for cohort 2. If deceased, up until passing away.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Universitaire Ziekenhuizen KU Leuven

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
July 30, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
August 31, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2029

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 3, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 14, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 17, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 17, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 14, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • S71965

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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