An observational study in Typical Development, Obsessive Compulsive Disorder and Conduct Disorder, sponsored by National Institute of Mental Health (NIMH). Recruiting at 1 site in United States. Open to participants aged 6 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-09-25.
Sponsored by National Institute of Mental Health (NIMH) · Observational
Background:
Impulsivity is acting 'without thinking.' Compulsivity is being overly inflexible. People vary in how impulsive or compulsive they are. Extreme versions of these behaviors play a role in mental disorders. Researchers want to study changes in the brain to learn more about these behaviors. Differences in genes may also play a role.
Objective:
To learn about genetic \& brain features that explain why levels of impulsivity and compulsivity vary across people.
Eligibility:
People ages 6 - 80
Design:
Participants will be screened with a medical history and medical record review.
Participants will talk about their mental and behavioral development. They may discuss topics like drug use and sexual activity. They will complete surveys about their compulsivity and impulsivity. Parents of child participants may also complete these surveys.
Participants may take memory, attention, and thinking tests. They may give blood or saliva samples for gene studies and they may give blood to make induced pluripotent stem cells. Participants may have their face and irises photographs taken.
Participants may have a magnetic resonance imaging scan. It will take pictures of their brain. The scanner is shaped like a cylinder. Participants will lie on a table that slides in and out of the scanner. A coil will be placed over their head. They will lie still, watch a movie, and play a game.
Participants may ask family members to join the study. Researchers are particularly interested in recruiting twin pairs to the study.
Participants under age 25 may repeat these tests every 1-2 years until they turn 25 or until the study ends. For those over age 25, participation will last less than 1 month.
Study Description:
Many neuropsychiatric disorders have extreme impairing impulsivity and compulsivity behaviors at their core. We hypothesized that the development of symptoms of impulsivity and compulsivity during childhood/adolescence and early adulthood will be associated with atypical trajectories of brain features including cortical glutamate (the main excitatory neurotransmitter) and functional/structural brain connectivity. Additionally, we hypothesize that cortical glutamate will be under genetic control (i.e., heritable) and that common genetic variant risk for disorders characterized by extreme impulsivity (e.g., attention deficit hyperactivity disorder) and by extreme compulsivity (e.g., obsessive compulsive disorder, autism spectrum disorder) will also be associated with atypical cortical glutamate trajectories. To elucidate the relationships between the developing brain, compulsivity/impulsivity and genomics, we will collect clinical assessments including clinician-led interviews, neurobehavioral assessments, neuroimaging data, and genomic samples using 1) a prospective longitudinal design to answer developmental hypotheses; 2) a twin design to assess heritability hypotheses.
Objectives:
Primary Objective:
A) To assess the effects of impulsivity and compulsivity on the developmental trajectories of cortical glutamate.
B) To determine the heritability of cortical glutamate.
Secondary Objectives:
A) To establish the reliability of glutamate measurements.
B) To examine the impact of atypical glutamate levels on developing structural and functional connections within the fronto-striatal circuits.
C) To assess within twin pair differences in neurodevelopmental markers (cortical glutamate, structural/functional MRI) in relation to differences in symptom domains.
Endpoints:
Primary Endpoint:
A) Age-related change in cortical glutamate levels and its moderation by individual differences in levels of impulsivity and compulsivity.
B) Heritability of cortical glutamate (proportion of variance explained by additive genetic factors).
Secondary Endpoints:
A) 1) Glutamate levels estimated at 3 Tesla at short intervals to establish test-retest reliability.
2) Glutamate levels estimated at both 3 Tesla and 7 Tesla (cross scanner validation).
B) Measures of the brain's structural and functional connectivity.
C) Within twin-pair differences in neurodevelopmental markers symptom domains (impulsivity/compulsivity).
635 studies on the registry are indexed under Obsessive-Compulsive Disorder; 166 are open to participants now.
This study's planned enrollment of 1,100 is above the median of 133 across 86 observational studies indexed under Obsessive-Compulsive Disorder.
Browse Obsessive-Compulsive Disorder studies →National Institute of Mental Health (NIMH) is the lead sponsor of 367 studies on the registry; 45 are open to participants now.
Of its 25 completed or terminated interventional studies of FDA-regulated products, 24 (96%) have results posted.
Counted across the registry records on this site, refreshed daily.
Individuals between 6 and 80 years of age with a wide range of impulsivity/compulsivity behaviors - ranging from normal to mildly/extremely impaired - will be recruited. No specific demographic groups will be targeted. Recruitment will be mainly done in the District of Columbia/Maryland/Virginia area, however some participants might travel from elsewhere.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
In order to be eligible to participate in this study, an individual must meet all of the following criteria:
EXCLUSION CRITERIA:
An individual who meets any of the following criteria will be excluded from participation in this study:
Additional exclusion criteria for optional MRI procedure:
1. Individuals who are not able to receive an MRI (e.g., metal bioimplants, claustrophobia, inability to lie flat on their backs, pregnant women, and any other for MRI scanning according to the NMR Center MRI safety guidelines).
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Individuals between 6 and 80 years of age with a wide range of impulsivity/compulsivity behaviors - ranging from normal to mildly/extremely impaired.
Glutamate concentration measured using Magnetic Resonance Spectroscopy
Age-related change in cortical glutamate levels and its moderation by individual differences in levels of impulsivity and compulsivity.
Time frame: Yearly if possible
Heritability of cortical glutamate (proportion of variance explained by additive genetic factors).
Degree to which glutamate levels are under genetic control.
Time frame: Baseline
Structural and functional connectivity
Structural and functional connectivity measured throughout development using Magnetic Resonance Imaging.
Time frame: Yearly if possible
Glutamate levels
Glutamate measurement at 7 Tesla is now the gold standard for glutamate measurements, against which we will compare measurements at 3 Tesla.
Time frame: weeks to months
Differences in glutamate levels and other neurodevelopmental markers within twin pairs.
Differences in twin characteristics will be measured through clinical symptom assessment, biomarkers, Magnetic Resonance Imaging, neuropsychological testing, and questionnaires.
Time frame: Yearly if possible
Plan to share: Yes — All de-identified medical information will be placed in a NIH repository (e.g., Biomedical Translational Research Information System (BTRIS)) in accordance to NIH policies. We will also share genomic and phenotypic data in controlled access databases such as dbGAP (database of Genotypes and Phenotypes). Other databases may be used as approved by NIH for the sharing of de-identified data.
Supporting information: Study protocol
Time frame: The timeline for data sharing will follow the NHGRI Genomic Data Sharing Policy. Currently data is deposited following IRB review once the study data collection is complete and the data has undergone quality control steps.
Access criteria: Access requests for specific research purposes using NIH controlled-access data are reviewed by NIH Data Access Committees (DACs).
Started Sep 2022 (actual). Primary completion is estimated for Dec 2030, 99 months after the start.
Of 27 observational studies under Obsessive-Compulsive Disorder, half reached primary completion within 68 months of starting (the median), counting those still running; a quarter within 41 and three quarters within 84. This study's planned 99 months is above that.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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