ADHDNCT07663383
Evaluation of Benign Joint Hypermobility and Serum Prolidase Levels in Children Diagnosed With Attention-Deficit/Hyperactivity Disorder (ADHD) Compared to Healthy Controls
An observational study of ADHD and Benign Joint Hypermobility Syndrome, run by Antalya Training and Research Hospital at 1 site in Turkey (Türkiye).
Trial summary
This cross-sectional observational study investigates the clinical and biochemical relationship between Attention-Deficit/Hyperactivity Disorder (ADHD) and Benign Joint Hypermobility Syndrome (BJHS) in pediatric patients. Read more about this study
- Who is it for?
- Ages 6 to 12 yearsHealthy volunteers can take part
- Conditions the study is for
- ADHD, Benign Joint Hypermobility Syndrome, ADHD - Attention Deficit Disorder With Hyperactivity
- How many people
- 171 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Apr 2025to 11 Oct 2025
- Phase
- Observational
- 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 6 to 12 years
- All sexes
- Healthy volunteers accepted
- Child
Study population: The study population consisted of children aged 6 to 12 years, including 86 patients diagnosed with Attention-Deficit/Hyperactivity Disorder (ADHD) according to DSM-5 criteria and 85 age- and sex-matched healthy controls. Patients were recruited from the Child and Adolescent Psychiatry outpatient clinic of Antalya Training and Research Hospital. Control subjects were selected from the general pediatric outpatient department. All participants were evaluated for ADHD symptom severity, joint hypermobility, and serum prolidase levels.
Who may be able to join
- Children aged between 6 and 12 years
- ADHD diagnosis based on DSM-5 criteria (for patient group)
- Healthy children with no known psychiatric or systemic disease (for control group)
- Willingness of the parents or legal guardians to participate and provide informed consent
- Ability to complete the required clinical assessments (CPRS-R:S, Beighton Score, blood sample)
Who cannot join
- Presence of chronic systemic diseases (e.g., autoimmune disorders, connective tissue diseases, metabolic syndromes)
- History of neurodegenerative or severe neurological disorders Intellectual disability or autism spectrum disorder diagnosis
- Use of medications that may affect prolidase enzyme activity (e.g., corticosteroids, immunosuppressants)
- Any orthopedic or musculoskeletal condition interfering with Beighton assessment
- Incomplete clinical or laboratory data
- Refusal to participate or lack of parental consent
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Antalya Training and Research Hospital
Antalya, Muratpaşa, 07100
About this study
This cross-sectional observational study investigates the clinical and biochemical relationship between Attention-Deficit/Hyperactivity Disorder (ADHD) and Benign Joint Hypermobility Syndrome (BJHS) in pediatric patients. The primary objective is to evaluate the prevalence of BJHS in children diagnosed with ADHD and compare serum prolidase levels with those of healthy controls. The study also explores whether the severity of ADHD symptoms correlates with serum prolidase activity. Clinical assessments include the Conners Parent Rating Scale, Beighton Score, and serum prolidase measurement using ELISA. This research aims to provide new insights into the potential connective tissue-neurodevelopmental link and contribute to early screening frameworks for children with ADHD.
Read the detailed description
Attention-Deficit/Hyperactivity Disorder (ADHD) is a prevalent neurodevelopmental disorder characterized by inattention, hyperactivity, and impulsivity, often presenting in early childhood. Although traditionally viewed as a purely behavioral and neurochemical condition, increasing evidence suggests a potential overlap with systemic and somatic findings, including those related to connective tissue disorders. One such condition is Benign Joint Hypermobility Syndrome (BJHS), a clinical entity involving increased joint flexibility due to altered collagen structure or metabolism.
Recent hypotheses have proposed a shared pathophysiological basis between neurodevelopmental disorders and connective tissue abnormalities, possibly mediated by enzymatic and inflammatory pathways. Prolidase is a cytosolic exopeptidase that plays a key role in collagen turnover and proline recycling. It has been implicated in various connective tissue disorders and may also influence neuroinflammatory processes. Thus, prolidase activity may serve as a biochemical bridge between BJHS and ADHD.
This cross-sectional observational study was conducted to investigate the clinical and biochemical associations between ADHD and BJHS in a pediatric population. Specifically, the study aimed to:
- determine the frequency and severity of joint hypermobility in children diagnosed with ADHD,
- compare Beighton Scores between ADHD and healthy control groups,
- measure and compare serum prolidase enzyme levels between both groups, and
- assess whether prolidase activity and hypermobility scores correlate with ADHD symptom severity and subtype (predominantly inattentive, hyperactive/impulsive, or combined presentation).
A total of 171 children aged 6 to 12 years participated in the study: 86 with a clinical diagnosis of ADHD (based on DSM-5 criteria) and 85 age- and sex-matched healthy controls without psychiatric or systemic illnesses. Participants in the ADHD group were recruited from the Child and Adolescent Psychiatry Department of Antalya Training and Research Hospital. Control subjects were selected from the general pediatric outpatient population, ensuring the absence of known neurodevelopmental or rheumatological disorders.
All participants underwent a standardized assessment battery. ADHD symptom severity was quantified using the Conners' Parent Rating Scale-Revised: Short Form (CPRS-R:S), which also allowed classification into ADHD subtypes. Joint hypermobility was assessed using the Beighton scoring system, with a threshold score ≥4 indicating hypermobility. Sociodemographic data were collected via structured interviews with caregivers. Venous blood samples were obtained to determine serum prolidase levels, analyzed using a validated ELISA method.
Data were statistically analyzed to evaluate group differences in Beighton Scores and prolidase levels, as well as correlations between biochemical markers, ADHD severity scores, and ADHD subtype classifications. Subgroup analyses were also conducted to assess whether prolidase activity or joint hypermobility was more strongly associated with specific ADHD presentations (e.g., inattentive vs. combined type).
By integrating clinical, physical, and biochemical data, this study seeks to offer a multidimensional perspective on ADHD, moving beyond traditional neurocognitive models. The findings may support the development of new screening and diagnostic strategies, particularly for pediatric patients who present with both behavioral symptoms and physical signs such as joint hypermobility. Additionally, this research may help identify candidate biomarkers for early intervention and interdisciplinary assessment in child psychiatry and pediatric rehabilitation settings.
- Conditions
- ADHD, Benign Joint Hypermobility Syndrome, ADHD - Attention Deficit Disorder With Hyperactivity, ADHD - Combined Type, ADHD - Inattentive Type
- Keywords
- adhd, bjhs, joint hypermobility, beighton score, prolidase
- Medical subject headings
- Attention Deficit Disorder with Hyperactivity, Joint Instability
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Group 1 Name: ADHD Group Type: Observational Cohort | Children aged 6 to 12 years who were clinically diagnosed with Attention-Deficit/Hyperactivity Disorder (ADHD) according to DSM-5 criteria. Participants in this cohort were recruited from the Child and Adolescent Psychiatry outpatient clinic of Antalya Training and Research Hospital. Each child underwent a detailed clinical evaluation including the Conners' Parent Rating Scale-Revised: Short Form (CPRS-R:S) to determine ADHD symptom severity and subtype. Joint hypermobility was assessed using the Beighton Score, and venous blood samples were collected to measure serum prolidase enzyme activity using ELISA. No therapeutic intervention was applied; this is a non-interventional observational group. | |
| Group 2 Name: Control Group Type: Observational Cohort | This group consisted of age- and sex-matched healthy children between 6 and 12 years of age with no history of psychiatric, neurological, or systemic illness. Control participants were selected from the general pediatric outpatient population and underwent the same evaluations as the ADHD group. These included the Conners' Parent Rating Scale-Revised: Short Form (CPRS-R:S), Beighton Score assessment for joint hypermobility, and serum prolidase measurement via ELISA. The purpose of this group was to provide a baseline comparison for clinical and biochemical parameters without any intervention applied. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence of comorbid Benign Joint Hypermobility Syndrome (BJHS) in children with ADHD
The primary outcome is to evaluate the incidence of Benign Joint Hypermobility Syndrome (BJHS) among children diagnosed with Attention Deficit Hyperactivity Disorder (ADHD), compared to healthy controls. Diagnosis of BJHS will be based on a Beighton score ≥5 and clinical evaluation.
Measured: At enrollment (single visit)
Secondary outcomes (3)
Beighton Score for Joint Hypermobility
Generalized joint hypermobility will be assessed using the Beighton scoring system (range: 0-9), with a cutoff value of ≥5/9 as a diagnostic threshold. The total Beighton scores of children with ADHD (ages 6-12) will be compared to healthy controls.
Measured: At enrollment (single visit)
Serum Prolidase Level
Fasting venous blood samples will be collected from all participants and serum prolidase levels will be measured using ELISA. Prolidase enzyme activity (U/L) will be compared between the ADHD group and healthy controls.
Measured: At enrollment (single visit)
Sociodemographic Characteristics
Sociodemographic data including age (in years), sex, height (in cm), weight (in kg), and socioeconomic status (classified as 0: low, 1: moderate, 2: high) will be collected and compared between groups.
Measured: At enrollment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Jun 2026
- Study start1 Apr 2025
- Primary completion1 Sep 2025
- Study completion11 Oct 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for ADHDStudies 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
- Case crossover
- Time perspective
- Prospective
- Enrolment
- 171 participants (actual)
Sponsor and investigators
- Lead sponsor
- Antalya Training and Research Hospital
- Sponsor type
- Other government
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07663383
- Sponsor's protocol ID
- 130220253/2
- Status last verified
- May 2026
- First submitted
- 16 Aug 2025
- Last updated
- 23 Jun 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Individual participant data that underlie the results reported in this study (including de-identified demographic, clinical, and biochemical data such as age, sex, Conners' scores, Beighton scores, and serum prolidase levels) will be shared upon reasonable request to the corresponding investigator.
Study at a glance
From the registry record, last updated by the sponsor on 23 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of Benign Joint Hypermobility and Serum Prolidase Levels in Children Diagnosed With Attention-Deficit/Hyperactivity Disorder (ADHD) Compared to Healthy Controls
- ClinicalTrials.gov ID
- NCT07663383
- Acronym / sponsor ID
- 130220253/2
- Conditions
- ADHD, Benign Joint Hypermobility Syndrome, ADHD - Attention Deficit Disorder With Hyperactivity, ADHD - Combined Type, ADHD - Inattentive Type
- Keywords
- adhd, bjhs, joint hypermobility, beighton score, prolidase
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 171 participants (actual)
- Lead sponsor
- Antalya Training and Research HospitalOther government
- Study start
- 1 Apr 2025 (actual)
- Primary completion
- 1 Sep 2025 (actual)
- Study completion
- 11 Oct 2025 (actual)
- First posted
- 23 Jun 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 cross-sectional observational study investigates the clinical and biochemical relationship between Attention-Deficit/Hyperactivity Disorder (ADHD) and Benign Joint Hypermobility Syndrome (BJHS) in pediatric patients. The primary objective is to evaluate the prevalence of BJHS in children diagnosed with ADHD and compare serum prolidase levels with those of healthy controls. The study also explores whether the severity of ADHD symptoms correlates with serum prolidase activity. Clinical assessments include the Conners Parent Rating Scale, Beighton Score, and serum prolidase measurement using ELISA. This research aims to provide new insights into the potential connective tissue-neurodevelopmental link and contribute to early screening frameworks for children with ADHD.
Detailed description
Attention-Deficit/Hyperactivity Disorder (ADHD) is a prevalent neurodevelopmental disorder characterized by inattention, hyperactivity, and impulsivity, often presenting in early childhood. Although traditionally viewed as a purely behavioral and neurochemical condition, increasing evidence suggests a potential overlap with systemic and somatic findings, including those related to connective tissue disorders. One such condition is Benign Joint Hypermobility Syndrome (BJHS), a clinical entity involving increased joint flexibility due to altered collagen structure or metabolism.
Recent hypotheses have proposed a shared pathophysiological basis between neurodevelopmental disorders and connective tissue abnormalities, possibly mediated by enzymatic and inflammatory pathways. Prolidase is a cytosolic exopeptidase that plays a key role in collagen turnover and proline recycling. It has been implicated in various connective tissue disorders and may also influence neuroinflammatory processes. Thus, prolidase activity may serve as a biochemical bridge between BJHS and ADHD.
This cross-sectional observational study was conducted to investigate the clinical and biochemical associations between ADHD and BJHS in a pediatric population. Specifically, the study aimed to:
- determine the frequency and severity of joint hypermobility in children diagnosed with ADHD,
- compare Beighton Scores between ADHD and healthy control groups,
- measure and compare serum prolidase enzyme levels between both groups, and
- assess whether prolidase activity and hypermobility scores correlate with ADHD symptom severity and subtype (predominantly inattentive, hyperactive/impulsive, or combined presentation).
A total of 171 children aged 6 to 12 years participated in the study: 86 with a clinical diagnosis of ADHD (based on DSM-5 criteria) and 85 age- and sex-matched healthy controls without psychiatric or systemic illnesses. Participants in the ADHD group were recruited from the Child and Adolescent Psychiatry Department of Antalya Training and Research Hospital. Control subjects were selected from the general pediatric outpatient population, ensuring the absence of known neurodevelopmental or rheumatological disorders.
All participants underwent a standardized assessment battery. ADHD symptom severity was quantified using the Conners' Parent Rating Scale-Revised: Short Form (CPRS-R:S), which also allowed classification into ADHD subtypes. Joint hypermobility was assessed using the Beighton scoring system, with a threshold score ≥4 indicating hypermobility. Sociodemographic data were collected via structured interviews with caregivers. Venous blood samples were obtained to determine serum prolidase levels, analyzed using a validated ELISA method.
Data were statistically analyzed to evaluate group differences in Beighton Scores and prolidase levels, as well as correlations between biochemical markers, ADHD severity scores, and ADHD subtype classifications. Subgroup analyses were also conducted to assess whether prolidase activity or joint hypermobility was more strongly associated with specific ADHD presentations (e.g., inattentive vs. combined type).
By integrating clinical, physical, and biochemical data, this study seeks to offer a multidimensional perspective on ADHD, moving beyond traditional neurocognitive models. The findings may support the development of new screening and diagnostic strategies, particularly for pediatric patients who present with both behavioral symptoms and physical signs such as joint hypermobility. Additionally, this research may help identify candidate biomarkers for early intervention and interdisciplinary assessment in child psychiatry and pediatric rehabilitation settings.
Study design
- Observational model
- Case crossover
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Group 1 Name: ADHD Group Type: Observational Cohort | – | –Children aged 6 to 12 years who were clinically diagnosed with Attention-Deficit/Hyperactivity Disorder (ADHD) according to DSM-5 criteria. Participants in this cohort were recruited from the Child and Adolescent Psychiatry outpatient clinic of Antalya Training and Research Hospital. Each child underwent a detailed clinical evaluation including the Conners' Parent Rating Scale-Revised: Short Form (CPRS-R:S) to determine ADHD symptom severity and subtype. Joint hypermobility was assessed using the Beighton Score, and venous blood samples were collected to measure serum prolidase enzyme activity using ELISA. No therapeutic intervention was applied; this is a non-interventional observational group. |
| Group 2 Name: Control Group Type: Observational Cohort | – | –This group consisted of age- and sex-matched healthy children between 6 and 12 years of age with no history of psychiatric, neurological, or systemic illness. Control participants were selected from the general pediatric outpatient population and underwent the same evaluations as the ADHD group. These included the Conners' Parent Rating Scale-Revised: Short Form (CPRS-R:S), Beighton Score assessment for joint hypermobility, and serum prolidase measurement via ELISA. The purpose of this group was to provide a baseline comparison for clinical and biochemical parameters without any intervention applied. |
Who may qualify
- Ages
- 6 to 12 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child
- Study population
- The study population consisted of children aged 6 to 12 years, including 86 patients diagnosed with Attention-Deficit/Hyperactivity Disorder (ADHD) according to DSM-5 criteria and 85 age- and sex-matched healthy controls. Patients were recruited from the Child and Adolescent Psychiatry outpatient clinic of Antalya Training and Research Hospital. Control subjects were selected from the general pediatric outpatient department. All participants were evaluated for ADHD symptom severity, joint hypermobility, and serum prolidase levels.
Key inclusion criteria (5 listed)
- Children aged between 6 and 12 years
- ADHD diagnosis based on DSM-5 criteria (for patient group)
- Healthy children with no known psychiatric or systemic disease (for control group)
- Willingness of the parents or legal guardians to participate and provide informed consent
- Ability to complete the required clinical assessments (CPRS-R:S, Beighton Score, blood sample)
Key exclusion criteria (6 listed)
- Presence of chronic systemic diseases (e.g., autoimmune disorders, connective tissue diseases, metabolic syndromes)
- History of neurodegenerative or severe neurological disorders Intellectual disability or autism spectrum disorder diagnosis
- Use of medications that may affect prolidase enzyme activity (e.g., corticosteroids, immunosuppressants)
- Any orthopedic or musculoskeletal condition interfering with Beighton assessment
- Incomplete clinical or laboratory data
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Incidence of comorbid Benign Joint Hypermobility Syndrome (BJHS) in children with ADHD
Time frame: At enrollment (single visit)
The primary outcome is to evaluate the incidence of Benign Joint Hypermobility Syndrome (BJHS) among children diagnosed with Attention Deficit Hyperactivity Disorder (ADHD), compared to healthy controls. Diagnosis of BJHS will be based on a Beighton score ≥5 and clinical evaluation.
3 secondary outcomes
Beighton Score for Joint Hypermobility
Time frame: At enrollment (single visit)
Serum Prolidase Level
Time frame: At enrollment (single visit)
Sociodemographic Characteristics
Time frame: At enrollment
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 23 Jun 2026.
- Individual participant dataSharing planned: Yes. Individual participant data that underlie the results reported in this study (including de-identified demographic, clinical, and biochemical data such as age, sex, Conners' scores, Beighton scores, and serum prolidase levels) will be shared upon reasonable request to the corresponding investigator.
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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.
The record lists no contact. Use the official record to reach the sponsor.
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 ADHD and Benign Joint Hypermobility Syndrome, run by Antalya Training and Research Hospital 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 5 inclusion and 6 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 23 Jun 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 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?
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?
Incidence of comorbid Benign Joint Hypermobility Syndrome (BJHS) in children with ADHD (time frame: At enrollment (single visit)). 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 23 Jun 2026.