Schizophenia DisorderNCT07306468
Effects of Schizophrenia and Bipolar Disorder on Exercise Capacity, Pulmonary Function, and Quality of Life
An observational study of Schizophenia Disorder and Bipolar Disorder (BD), run by Çankırı Karatekin University at 1 site in Turkey (Türkiye).
Trial summary
This observational study aims to evaluate exercise capacity, pulmonary function, respiratory muscle strength, and quality of life in individuals diagnosed with schizophrenia and bipolar disorder. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Schizophenia Disorder, Bipolar Disorder (BD)
- What is being tested?
- Pulmonary Function Test, Respiratory Muscle Strength Evaluation and Quality of Life Assessment
- How many people
- 150 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Nov 2025to 1 Dec 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: The study population will consist of individuals diagnosed with schizophrenia or bipolar disorder who are currently receiving standard medical treatment at the Community Mental Health Center of Çankırı State Hospital. Participants will be aged between 18 and 65 years, literate, and willing to participate in the study. No sampling method will be applied; all eligible individuals who meet the inclusion criteria and provide informed consent will be enrolled. Based on a prior sample size analysis conducted using data collected under approved ethical clearance, the study aims to include a total of 150 participants-50 individuals in each diagnostic group (schizophrenia, bipolar disorder and healthy controls). This sample size is expected to provide sufficient statistical power to detect differences between groups in terms of exercise capacity, pulmonary function, respiratory muscle strength, and quality of life.
Who may be able to join
- Being volunteer for participation
- Being 18 to 65 age
Who cannot join
- Having any respiratory, cardiac, neurologic or orthopedic disease which may affect respiratory functions or exercise capacity
- Having any neuropsychiatric disease except schizophrenia or bipolar disorder
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Turkey (Türkiye)1 site, 1 recruiting
- Recruiting
Çankırı Karatekin University, Faculty of Health Sciences, Department of Physiotherapy and Rehabilitation
Çankırı, Çankırı, 18100
Furkan Özdemir, +905383264855, furkanozdemir@karatekin.edu.tr
About this study
Official title: Investigation of Exercise Capacity, Pulmonary Function, Respiratory Muscle Strength, and Quality of Life in Patients Diagnosed With Schizophrenia and Bipolar Disorder
This observational study aims to evaluate exercise capacity, pulmonary function, respiratory muscle strength, and quality of life in individuals diagnosed with schizophrenia and bipolar disorder. These psychiatric conditions are associated with sedentary lifestyles, metabolic side effects of psychotropic medications, and increased comorbidity risks, all of which may negatively impact physical fitness and respiratory health. By assessing cardiorespiratory endurance, pulmonary parameters (FVC, FEV₁), and respiratory muscle strength in this population, the study seeks to identify physiological limitations and contribute to the development of more effective rehabilitation strategies. The findings may support multidisciplinary approaches to improving physical health and overall quality of life in individuals with severe mental illness.
Read the detailed description
Schizophrenia is a mental disorder observed in approximately 4 out of every 1,000 individuals in the general population, with a morbidity rate of 0.72%. According to the Global Burden of Disease Study (2010), around 20,000 deaths occur annually due to schizophrenia-related causes. Bipolar disorder is recognized as a chronic and severe mental illness. Based on data from the World Health Organization's global burden of disease reports, bipolar disorder ranks among the top 20 diseases contributing to disability worldwide and holds the 6th position among mental disorders.
Schizophrenia and bipolar disorder are serious and chronic psychiatric conditions affecting millions of individuals globally. The prevalence of schizophrenia is approximately 1%, while bipolar disorder has a lifetime prevalence of 2-3%. These disorders not only involve neuropsychiatric symptoms but also significantly impact physical health. In individuals with these conditions, sedentary lifestyle habits, metabolic side effects of antipsychotic and mood-stabilizing medications, and increased comorbidity risks are associated with notable reductions in exercise capacity.
Moreover, physical inactivity and heightened inflammatory processes may adversely affect respiratory muscle strength and pulmonary function. Studies have shown that patients with schizophrenia exhibit significantly lower maximal oxygen consumption (VO₂max) and anaerobic threshold levels compared to healthy individuals. In bipolar disorder, depressive episodes are marked by reduced exercise capacity, while manic episodes often involve irregular and risky physical activities.
Additionally, both disorders are associated with significantly lower pulmonary function parameters (FVC, FEV₁) compared to the healthy population. Respiratory muscle strength, a relatively underexplored area, is gaining importance. In schizophrenia cases dominated by negative symptoms, reduced inspiratory muscle strength combined with insufficient physical activity can severely limit patients' quality of life and independence. Similarly, in bipolar disorder, impairments in pulmonary capacity and respiratory muscle strength negatively affect quality of life.
Quality of life in these individuals is closely linked not only to mental health but also to physical capacity and pulmonary function. Enhancing respiratory muscle strength and aerobic capacity may positively influence overall quality of life, social participation, and functional status. However, the existing literature remains limited and fragmented. There is a noticeable lack of studies that simultaneously evaluate exercise capacity, pulmonary function, and respiratory muscle strength in individuals with psychiatric disorders.
This study aims to contribute to the literature from a multidisciplinary perspective by jointly examining exercise capacity, pulmonary function, respiratory muscle strength, and quality of life in individuals diagnosed with schizophrenia and bipolar disorder. These individuals often exhibit unhealthy lifestyle habits and a tendency toward sedentary behavior, which are considered risk factors that may adversely affect physical fitness. Components of physical fitness include cardiorespiratory endurance and muscular endurance. In light of this information, a review of the literature reveals that data on pulmonary function, respiratory muscle strength, and endurance in individuals with schizophrenia and bipolar disorder are still limited. The findings obtained from this study may guide the development of more effective rehabilitation and physical health support programs for these populations.
- Conditions
- Schizophenia Disorder, Bipolar Disorder (BD)
- Being tested
- Pulmonary Function Test, Respiratory Muscle Strength Evaluation, Quality of Life Assessment, Exercise Capacity Assessment
- Keywords
- schizophrenia, bipolar disorder, respiratory functions, quality of life, exercise capacity
- Medical subject headings
- Bipolar Disorder, Schizophrenia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Pulmonary Function TestOther
Participants' respiratory functions will assess with pulmonary function test according to ATS/ERS criteria
Respiratory Muscle Strength EvaluationOther
Participants' respiratory muscle strenght will assess with maximal inspiratory pressure and maximal expiratory pressure assessment according to ATS/ERS criteria
Quality of Life AssessmentOther
Participants' quality of life will assess with WHOQOL-Bref questionnaire
Exercise Capacity AssessmentOther
Participants' exercise capacity will assess with 6 Minute Walk Test according to ATS/ERS criteria
| Study group | Role | What they receive |
|---|---|---|
| Schizophrenia | Patients diagnosed with schizophrenia Receives: Other: Pulmonary Function Test; Other: Respiratory Muscle Strength Evaluation; Other: Quality of Life Assessment; Other: Exercise Capacity Assessment | |
| Bipolar Disorder | Patients diagnosed with bipolar disorder Receives: Other: Pulmonary Function Test; Other: Respiratory Muscle Strength Evaluation; Other: Quality of Life Assessment; Other: Exercise Capacity Assessment | |
| Healthy Control | Participants who have any diagnosed diseases/disorders Receives: Other: Pulmonary Function Test; Other: Respiratory Muscle Strength Evaluation; Other: Quality of Life Assessment; Other: Exercise Capacity Assessment |
What is being measured
The primary outcome is the main question the study is designed to answer.
Maximum Inspiratory Pressure (MIP) measurement
MIP will be measured using a mouth pressure device on Day 1 of the intervention. The maximum inspiratory pressure (MIP) will be recorded in cmH₂O. Three assessments will be performed, and the highest value will be reported.
Measured: 1st day
Maximum Expiratory Pressure (MEP) measured in cmH₂O
MEP will be measured using a mouth pressure device on Day 1 of the intervention. The maximum expiratory pressure (MEP) will be recorded in cmH₂O. Three assessments will be performed, and the highest value will be reported.
Measured: 1st day
Forced Expiratory Volume in 1 Second (FEV1) measured in liters
FEV1 will be measured using spirometry on Day 1 of the intervention. The maximum expiratory volume in 1 second (FEV1) will be recorded in liters. Three assessments will be performed, and the highest value will be reported.
Measured: 1st day
Forced Vital Capacity (FVC) measured in liters
FVC will be measured using spirometry on Day 1 of the intervention. The forced vital capacity (FVC) will be recorded in liters. Three assessments will be performed, and the highest value will be reported.
Measured: 1st day
FEV1/FVC ratio measured as a percentage
FEV1/FVC ratio will be calculated using spirometry on Day 1 of the intervention.
The ratio of FEV1 to FVC will be expressed as a percentage. Three assessments will be performed, and the highest value will be reported.
Measured: 1st day
Peak Expiratory Flow (PEF) measurement
PEF will be measured using spirometry on Day 1 of the intervention. The peak expiratory flow (PEF) will be recorded in liters per minute. Three assessments will be performed, and the highest value will be reported.
Measured: 1st day
Secondary outcomes (2)
6-minute walk distance (6MWD) measured in meters
The 6-minute walk test will be conducted according to standardized procedures in a straight corridor. Participants will be instructed to walk as far as possible in 6 minutes with standardized encouragement. The total distance walked will be recorded in meters. If a test is interrupted, the distance completed will be recorded. Two assessments will be performed on the same day, separated by a 30-minute rest interval. The 6-minute walk distance (6MWD) will be measured in meters, and the best (highest) distance will be reported.
Measured: 1st day
WHOQOL-BREF total score measurement
Health-related quality of life will be assessed using the Turkish version of WHOQOL-BREF questionnaire. Participants will complete the 26-item survey at the 1st day. The total score will be calculated according to standardized scoring procedures and reported in points. Higher scores indicate better quality of life.
Measured: 1st day
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Dec 2025
- Study start1 Nov 2025
- Primary completion1 Nov 2026 (estimated)
- Study completion1 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Schizophenia DisorderStudies 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 150 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Çankırı Karatekin University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Furkan Özdemir, Çankırı Karatekin University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07306468
- Sponsor's protocol ID
- 2025-06-26
- Status last verified
- Dec 2025
- First submitted
- 25 Nov 2025
- Last updated
- 29 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 29 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Investigation of Exercise Capacity, Pulmonary Function, Respiratory Muscle Strength, and Quality of Life in Patients Diagnosed With Schizophrenia and Bipolar Disorder
- ClinicalTrials.gov ID
- NCT07306468
- Acronym / sponsor ID
- 2025-06-26
- Conditions
- Schizophenia Disorder, Bipolar Disorder (BD)
- Keywords
- schizophrenia, bipolar disorder, respiratory functions, quality of life, exercise capacity
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 150 participants (estimated)
- Lead sponsor
- Çankırı Karatekin UniversityUniversity, hospital or other
- Study start
- 1 Nov 2025 (actual)
- Primary completion
- 1 Nov 2026 (estimated)
- Study completion
- 1 Dec 2026 (estimated)
- First posted
- 29 Dec 2025 (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 observational study aims to evaluate exercise capacity, pulmonary function, respiratory muscle strength, and quality of life in individuals diagnosed with schizophrenia and bipolar disorder. These psychiatric conditions are associated with sedentary lifestyles, metabolic side effects of psychotropic medications, and increased comorbidity risks, all of which may negatively impact physical fitness and respiratory health. By assessing cardiorespiratory endurance, pulmonary parameters (FVC, FEV₁), and respiratory muscle strength in this population, the study seeks to identify physiological limitations and contribute to the development of more effective rehabilitation strategies. The findings may support multidisciplinary approaches to improving physical health and overall quality of life in individuals with severe mental illness.
Detailed description
Schizophrenia is a mental disorder observed in approximately 4 out of every 1,000 individuals in the general population, with a morbidity rate of 0.72%. According to the Global Burden of Disease Study (2010), around 20,000 deaths occur annually due to schizophrenia-related causes. Bipolar disorder is recognized as a chronic and severe mental illness. Based on data from the World Health Organization's global burden of disease reports, bipolar disorder ranks among the top 20 diseases contributing to disability worldwide and holds the 6th position among mental disorders.
Schizophrenia and bipolar disorder are serious and chronic psychiatric conditions affecting millions of individuals globally. The prevalence of schizophrenia is approximately 1%, while bipolar disorder has a lifetime prevalence of 2-3%. These disorders not only involve neuropsychiatric symptoms but also significantly impact physical health. In individuals with these conditions, sedentary lifestyle habits, metabolic side effects of antipsychotic and mood-stabilizing medications, and increased comorbidity risks are associated with notable reductions in exercise capacity.
Moreover, physical inactivity and heightened inflammatory processes may adversely affect respiratory muscle strength and pulmonary function. Studies have shown that patients with schizophrenia exhibit significantly lower maximal oxygen consumption (VO₂max) and anaerobic threshold levels compared to healthy individuals. In bipolar disorder, depressive episodes are marked by reduced exercise capacity, while manic episodes often involve irregular and risky physical activities.
Additionally, both disorders are associated with significantly lower pulmonary function parameters (FVC, FEV₁) compared to the healthy population. Respiratory muscle strength, a relatively underexplored area, is gaining importance. In schizophrenia cases dominated by negative symptoms, reduced inspiratory muscle strength combined with insufficient physical activity can severely limit patients' quality of life and independence. Similarly, in bipolar disorder, impairments in pulmonary capacity and respiratory muscle strength negatively affect quality of life.
Quality of life in these individuals is closely linked not only to mental health but also to physical capacity and pulmonary function. Enhancing respiratory muscle strength and aerobic capacity may positively influence overall quality of life, social participation, and functional status. However, the existing literature remains limited and fragmented. There is a noticeable lack of studies that simultaneously evaluate exercise capacity, pulmonary function, and respiratory muscle strength in individuals with psychiatric disorders.
This study aims to contribute to the literature from a multidisciplinary perspective by jointly examining exercise capacity, pulmonary function, respiratory muscle strength, and quality of life in individuals diagnosed with schizophrenia and bipolar disorder. These individuals often exhibit unhealthy lifestyle habits and a tendency toward sedentary behavior, which are considered risk factors that may adversely affect physical fitness. Components of physical fitness include cardiorespiratory endurance and muscular endurance. In light of this information, a review of the literature reveals that data on pulmonary function, respiratory muscle strength, and endurance in individuals with schizophrenia and bipolar disorder are still limited. The findings obtained from this study may guide the development of more effective rehabilitation and physical health support programs for these populations.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Schizophrenia | – | Other: Pulmonary Function Test, Other: Respiratory Muscle Strength Evaluation, Other: Quality of Life Assessment, Other: Exercise Capacity AssessmentPatients diagnosed with schizophrenia |
| Bipolar Disorder | – | Other: Pulmonary Function Test, Other: Respiratory Muscle Strength Evaluation, Other: Quality of Life Assessment, Other: Exercise Capacity AssessmentPatients diagnosed with bipolar disorder |
| Healthy Control | – | Other: Pulmonary Function Test, Other: Respiratory Muscle Strength Evaluation, Other: Quality of Life Assessment, Other: Exercise Capacity AssessmentParticipants who have any diagnosed diseases/disorders |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- The study population will consist of individuals diagnosed with schizophrenia or bipolar disorder who are currently receiving standard medical treatment at the Community Mental Health Center of Çankırı State Hospital. Participants will be aged between 18 and 65 years, literate, and willing to participate in the study. No sampling method will be applied; all eligible individuals who meet the inclusion criteria and provide informed consent will be enrolled. Based on a prior sample size analysis conducted using data collected under approved ethical clearance, the study aims to include a total of 150 participants-50 individuals in each diagnostic group (schizophrenia, bipolar disorder and healthy controls). This sample size is expected to provide sufficient statistical power to detect differences between groups in terms of exercise capacity, pulmonary function, respiratory muscle strength, and quality of life.
Key inclusion criteria (2 listed)
- Being volunteer for participation
- Being 18 to 65 age
Key exclusion criteria (2 listed)
- Having any respiratory, cardiac, neurologic or orthopedic disease which may affect respiratory functions or exercise capacity
- Having any neuropsychiatric disease except schizophrenia or bipolar disorder
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 |
|---|---|---|
| Pulmonary Function TestParticipants' respiratory functions will assess with pulmonary function test according to ATS/ERS criteria | Other | Bipolar Disorder, Healthy Control, Schizophrenia |
| Respiratory Muscle Strength EvaluationParticipants' respiratory muscle strenght will assess with maximal inspiratory pressure and maximal expiratory pressure assessment according to ATS/ERS criteria | Other | Bipolar Disorder, Healthy Control, Schizophrenia |
| Quality of Life AssessmentParticipants' quality of life will assess with WHOQOL-Bref questionnaire | Other | Bipolar Disorder, Healthy Control, Schizophrenia |
| Exercise Capacity AssessmentParticipants' exercise capacity will assess with 6 Minute Walk Test according to ATS/ERS criteria | Other | Bipolar Disorder, Healthy Control, Schizophrenia |
Primary outcome
Maximum Inspiratory Pressure (MIP) measurement
Time frame: 1st day
MIP will be measured using a mouth pressure device on Day 1 of the intervention. The maximum inspiratory pressure (MIP) will be recorded in cmH₂O. Three assessments will be performed, and the highest value will be reported.
Maximum Expiratory Pressure (MEP) measured in cmH₂O
Time frame: 1st day
MEP will be measured using a mouth pressure device on Day 1 of the intervention. The maximum expiratory pressure (MEP) will be recorded in cmH₂O. Three assessments will be performed, and the highest value will be reported.
Forced Expiratory Volume in 1 Second (FEV1) measured in liters
Time frame: 1st day
FEV1 will be measured using spirometry on Day 1 of the intervention. The maximum expiratory volume in 1 second (FEV1) will be recorded in liters. Three assessments will be performed, and the highest value will be reported.
Forced Vital Capacity (FVC) measured in liters
Time frame: 1st day
FVC will be measured using spirometry on Day 1 of the intervention. The forced vital capacity (FVC) will be recorded in liters. Three assessments will be performed, and the highest value will be reported.
FEV1/FVC ratio measured as a percentage
Time frame: 1st day
FEV1/FVC ratio will be calculated using spirometry on Day 1 of the intervention. The ratio of FEV1 to FVC will be expressed as a percentage. Three assessments will be performed, and the highest value will be reported.
Peak Expiratory Flow (PEF) measurement
Time frame: 1st day
PEF will be measured using spirometry on Day 1 of the intervention. The peak expiratory flow (PEF) will be recorded in liters per minute. Three assessments will be performed, and the highest value will be reported.
2 secondary outcomes
6-minute walk distance (6MWD) measured in meters
Time frame: 1st day
WHOQOL-BREF total score measurement
Time frame: 1st day
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Dec 2025.
- Individual participant dataSharing planned: No
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Schizophenia Disorder and Bipolar Disorder (BD), run by Çankırı Karatekin University at 1 site in Turkey (Türkiye).
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 2 inclusion and 2 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: looking for participants now, as of the sponsor's last update on 29 Dec 2025. 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 Turkey (Türkiye). 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. 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Furkan Özdemir, PT, Ph.D. (+905383264855, furkanozdemir@karatekin.edu.tr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Maximum Inspiratory Pressure (MIP) measurement (time frame: 1st day). The study lists 6 primary outcomes in all. 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 29 Dec 2025.