The Effects of Aerobic Exercise and Mindful Breathing on Individuals With Major Depressive Disorder in Saudi Arabia (MDD/AE/MB)

June 1, 2026 updated by: Saad Bin Muaythir, University of Pretoria

The Effects of Aerobic Exercise and Mindful Breathing on Symptom Severity and Quality of Life in Individuals With Major Depressive Disorder in Saudi Arabia: A Randomised Clinical Trial Protocol

The goal of this Randomized Clinical Trial is to evaluate the effectiveness of aerobic exercise (AE) and mindful breathing (MB) on depressive symptom severity and quality of life (QoL), in adults with MDD. The main question is: Does aerobic exercise and mindful breathing delivery reduce depressive symptom severity and improve quality of life more effectively than standard psychiatric care? The aims to answer are:

  1. To determine the effect of aerobic exercise interventions on depressive symptoms of individuals diagnosed with MDD.
  2. To determine the effect of aerobic exercise interventions on health-related quality of life among individuals diagnosed with MDD.
  3. To determine the effect of mindful breathing exercises on depressive symptoms among individuals diagnosed with MDD.
  4. To determine the effect of the mindful breathing exercise intervention on quality of life amongst individuals diagnosed with MDD.

Participants will be randomized into three groups:

  1. 45 minutes of moderate AE (60-75% HRR);
  2. 15 minutes of guided mindful breathing (6 breaths/minute);
  3. a waitlist control receiving standard care. *Interventions will occur three times a week for 16 weeks.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Major Depressive Disorder (MDD) is a leading cause of global disability, with many patients showing suboptimal responses to conventional pharmacological treatments. Evidence suggests that aerobic exercise (AE) and mindful breathing (MB) can serve as powerful non-pharmacological modulators of the central and autonomic nervous systems. This protocol outlines a randomized clinical trial (RCT) to evaluate the individual and synergistic effects of these interventions in a Saudi Arabian clinical population.

Major Depressive Disorder (MDD) is no longer viewed merely as a psychological condition but as a systemic, multi-faceted public health crisis. According to the World Health Organization and the latest Global Burden of Disease (GBD) analysis, MDD is a primary driver of global disability, defined by persistent feelings of sadness, anhedonia, sleep disturbances, and diminished capacity for daily functioning . Globally, it affects more than 280 million people.

In Saudi Arabia, the rising prevalence of MDD necessitates a shift toward "Integrative Psychiatry," where lifestyle medicine serves as a core pillar. Despite the availability of pharmacological and psychotherapeutic treatments, many individuals experience suboptimal outcomes, relapse, or treatment resistance, with the STAR*D study highlighting that only about one-third of patients achieve full remission after their first course of antidepressant medication . Furthermore, the side effects of conventional medications, such as weight gain and metabolic syndrome, often lead to premature discontinuation.

While the individual antidepressant effects of exercise and mindful breathing are well-documented, significant gaps remain. Existing literature indicates that AE "primes" the brain by increasing neuroplasticity and reward processing. Mindful breathing, conversely, stabilizes the autonomic nervous system and reduces anxiety. Combining these two low-cost, non-pharmacological interventions may provide a superior "biopsychosocial" approach to MDD recovery that neither could achieve alone. Modern psychiatry recognizes that a patient can be "less depressed" while still having a poor Quality of Life (QoL). Exercise is uniquely positioned to improve QoL because its benefits are "transdiagnostic", improving physical vitality, sleep quality, and social engagement simultaneously.

and a baseline Hamilton Depression Rating Scale (HAM-D) score ≥ 17.

Study Type

Interventional

Enrollment (Estimated)

60

Phase

  • Not Applicable

Contacts and Locations

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

Study Contact

Study Locations

  • Saudi Arabia
      • Al Kharj, Saudi Arabia
        • Erada Hospital and Mental Health in Al Kharj
        • Contact:
      • Riyadh, Saudi Arabia
        • Erada complex and Mental Health in Riyadh
        • Contact:

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

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Adults aged 18-60 years with a formal diagnosis of Major Depressive Disorder (MDD) based on DSM-5-TR or ICD-10 criteria.
  2. A baseline score of ≥ 17 on the Hamilton Depression Rating Scale (HAM-D) is required to ensure a moderate-to-severe symptom profile

Exclusion Criteria:

  1. Patients with high suicidal ideation
  2. Patients with a history of psychosis or bipolar disorder
  3. Patient with physical contraindications to exercise (e.g., unstable cardiovascular disease).
  4. Concurrent participation in other structured exercise/mindfulness trials.

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

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Aerobic Exercise (AE)

The AE protocol is designed to achieve the moderate-intensity threshold (SMD = -0.91), which has been identified as the most effective for symptom reduction (16).

  • Warm-up: 5-10 minutes of low-intensity walking and dynamic stretching.
  • Core Phase: 30 minutes of continuous aerobic activity (walking or Stationary Cycling).
  • Intensity Monitoring: Heart rate (HR) will be monitored using wearable sensors. Target intensity is set at 60-75% of the Heart Rate Reserve (HRR) or a Rating of Perceived Exertion (RPE) of 12-14 on the Borg Scale.
  • Cool-down: 5 minutes of slow walking and static stretching.
Other: Aerobic exercise
Aerobic or cardiovascular exercise is characterized by activities that engage large muscle groups, including walking, jogging, or cycling. Regular aerobic exercise can improve cardiovascular health, endurance, and overall fitness.
Other Names:
  • walking
  • cardiovascular exercise
Experimental: Mindful Breathing (MB)

The MB protocol focuses on "Top-Down" emotional regulation and "Bottom-Up" autonomic stabilisation.

  • Technique: Participants will be taught Diaphragmatic Resonant Breathing. This involves inhaling through the nose for four (4) seconds and exhaling slowly for six (6) seconds (approximately 6 deep breaths per minute).
  • Mindfulness Component: During the breathing, participants are instructed to maintain "non-judgmental awareness," acknowledging stray thoughts and gently returning focus to the sensation of air entering and leaving the body.
  • Duration: 15 minutes per session, conducted in a seated, comfortable position with eyes closed or a soft gaze.
Other: Mindful Breathing
Mindful breathing can include diaphragmatic breathing, deep breathing, and controlled breathing techniques, which focus on regulating and optimizing the process of inhalation and exhalation. These techniques enhance respiratory function, increase lung capacity, and promote relaxation by activating the parasympathetic nervous system. Therefore, they have been used in various therapeutic contexts to manage stress, anxiety, and mood disorders, including MDD, by regulating emotions and the stress response.
Other Names:
  • deep breathing
  • diaphragmatic breathing
Other: Control Group (Standard Care) Standard Treatment
Participants will continue their prescribed pharmacological treatment and any existing psychotherapy and physiotherapy sessions.
Other: Aerobic exercise
Aerobic or cardiovascular exercise is characterized by activities that engage large muscle groups, including walking, jogging, or cycling. Regular aerobic exercise can improve cardiovascular health, endurance, and overall fitness.
Other Names:
  • walking
  • cardiovascular exercise
Other: Mindful Breathing
Mindful breathing can include diaphragmatic breathing, deep breathing, and controlled breathing techniques, which focus on regulating and optimizing the process of inhalation and exhalation. These techniques enhance respiratory function, increase lung capacity, and promote relaxation by activating the parasympathetic nervous system. Therefore, they have been used in various therapeutic contexts to manage stress, anxiety, and mood disorders, including MDD, by regulating emotions and the stress response.
Other Names:
  • deep breathing
  • diaphragmatic breathing

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Depressive symptom severity
Time Frame: Baseline, Week 4,8, and a 16-week

Depressive symptom severity will be assessed using the Hamilton Depression Rating Scale (HAM-D), with total scores ranging from 0 to 52. Higher scores indicate more severe depressive symptoms.

For MDD, a baseline Hamilton Depression Rating Scale (HAM-D) score of ≥ 17 is required. Reduction in Hamilton Depression Rating Scale (HAM-D) scores is the primary outcome measure.
Baseline, Week 4,8, and a 16-week

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Quality of life (QoL) 1: Quality of Life (WHOQOL-BREF)
Time Frame: WHOQOL-BREF: baseline and week 16.
Quality of life will be assessed using the World Health Organization Quality of Life-BREF (WHOQOL-BREF), which generates domain scores transformed to a scale ranging from 0 to 100. Higher scores indicate a better quality of life
WHOQOL-BREF: baseline and week 16.
Quality of life (QoL)2 : Anxiety Symptoms
Time Frame: Baseline, Week 4,8, and a 16-week
Anxiety symptoms will be assessed using the Beck Anxiety Inventory (BAI), a 21-item self-report questionnaire with total scores ranging from 0 to 63. Higher scores indicate greater anxiety severity.
Baseline, Week 4,8, and a 16-week
Quality of life (QoL) 3: Sleep Quality
Time Frame: Baseline, Week 4, Week 8, and Week 16.
Sleep quality will be assessed using the Pittsburgh Sleep Quality Index (PSQI), a 19-item questionnaire with total scores ranging from 0 to 21. Higher scores indicate poorer sleep quality.
Baseline, Week 4, Week 8, and Week 16.

Collaborators and Investigators

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

Sponsor

University of Pretoria

Investigators

  • Principal Investigator: Saad Bin Muaythir, Master

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 (Estimated)

June 15, 2026

Primary Completion (Estimated)

October 14, 2026

Study Completion (Estimated)

November 14, 2026

Study Registration Dates

First Submitted

May 27, 2026

First Submitted That Met QC Criteria

June 1, 2026

First Posted (Actual)

June 4, 2026

Study Record Updates

Last Update Posted (Actual)

June 4, 2026

Last Update Submitted That Met QC Criteria

June 1, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 680/2024

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Indirect identifiers will be used through coded participant IDs. Direct identifiers will be stored separately from research data. Use participant codes on all study forms; store consent forms separately; keep electronic data on password-protected/encrypted devices or servers; keep paper CRFs in locked cabinets; restrict access to PI and authorized research staff only.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

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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