Examination of the Dynamic Relationships of Sleep, Physical Activity, and Circadian Rhythmicity With Neurobehavioral Heterogeneity in ADHD

BEHAVIORAL

Go/No-Go Task

A computerized test in which participants are presented with red and green spaceship stimuli. They are told to press the spacebar in response to green spaceships (80% of trials) and withhold their response to red spaceships (20% of trials).

BEHAVIORAL

Delay discounting task

Participants make decisions between smaller, immediate rewards and larger, delayed rewards. The amount of the immediate reward and delay time are manipulated to identify individual delay discounting curves, or how the reward value decreases as a function of delay.

BEHAVIORAL

Mirror Tracing Persistence Task

A computerized test in which participants trace a star line drawing with a computer cursor using a trackpad with reversed directional controls. There are increasing levels of difficulty with participants being told they could quit the task during the very hard third star that they try to trace.

BEHAVIORAL

Spatial Span

Participants are instructed to attend to a computer screen to keep track of the order in which a happy face stimuli appears in a sequence of boxes positioned on the screen. They are presented with 2 trials at each level of difficulty, increasing from 2 stimuli by 1 additional stimuli per trial until they respond incorrectly for both trials within a level. There are two task conditions, forward and backward span, with the participant responding in the reverse order that the stimuli were presented for backward span.

BEHAVIORAL

Stop Signal Task

A computerized test in which participants are presented with a right or left facing arrow and are instructed to press a response button indicating the direction of the arrow. On 25% of the trials, an auditory beep is presented (i.e., stop signal) following the onset of the arrow (i.e., go signal) and participants are instructed to withhold their response when they hear the stop signal.

BEHAVIORAL

Flanker task

A computerized test in which a group of arrows are presented on the screen with the central arrow (target) pointing in the same/opposite direction as the 4 surrounding arrows (flankers). Participants are instructed to respond as quickly and accurately as possible to the central target arrow.

Total Activity Counts (TAC)

Time frame: Two-week, real-time period of at-home activity monitoring

Using an actigraph, this study will collect daily physical activity levels of children. The actigraphic measure, total activity counts (TAC), will capture the number of times a child engages in periods of physical activity during the day and night.

Children's Sleep Health Questionnaire (CSHQ) Total Score

Time frame: Within six months prior to the first research appointment.

Sleep quality will be measured using the total score from the parent reported questionnaire asking about sleep duration, sleep disturbances, and sleep quality.

ADHD-related Symptoms

Time frame: Within six months prior to the first research appointment.

Parents will complete a diagnostic interview and rating scales reporting on ADHD symptoms, cognitive disengagement syndrome, irritability and emotion dysregulation.

Mean Fractional Anisotropy (FA)

Time frame: Completed during the MRI scan on Day 15

Mean fractional anisotropy (FA) is a structural connectivity diffusion weighted imaging outcomes. It is a value that represents the overall degree of directional diffusion within that area, with higher values indicating more organized/connectivity, aligned white matter fibers, and lower values suggesting less organized fibers. Mean fractional anisotropy (FA) will be assessed in six fronto-subcortical tracts of interest including (1) OFC-limbic striatum, (2) dlPFC-executive striatum, (3) ACC-limbic striatum, (4) ACC-executive striatum, (5) OFC- and (6) ACC-amygdala in each hemisphere.

Stop Signal Reaction Time

Time frame: Task will be completed on Day 15

Measure of inhibitory control from the stop signal task based on the mean stop signal delay and mean go reaction time.

Congruency Effect on Reaction Time

Time frame: Task will be completed on Day 15

Difference in reaction time on correct response trials from the flanker task with congruent versus incongruent flanking stimuli.

Commission Errors

Time frame: Task will be completed on Day 15

Percentage of incorrect responses on no-go trials during the go/no-go task.

Backward Span Accuracy

Time frame: Task will be completed on Day 15

Total number of correct trials for the digit and spatial span tasks (separately), backwards span condition

Delay Discounting Area Over the Curve (AOC)

Time frame: Task will be completed on Day 15

Area over the curve (AOC) is a measure of the extent to which an individual discounts a reward as a function of delay. We will assess this measure during delay discounting tasks with different types of rewards (money and game time).

Mirror Tracing Persistance Task Latency to Quit

Time frame: Task will be completed on Day 15

During the very hard star condition of the MTPT, participants may choose to quit the task. This is the amount of time that passes until they quit the task.

Total Sleep Time (TST)

Time frame: Two-week, real-time period of at-home activity monitoring

Total sleep time (TST) will be collected using a wearable actigraph wristband. This variable is reported in minutes.

Wake After Sleep Onset (WASO)

Time frame: Two-week, real-time period of at-home activity monitoring

This variable is collected using a wearable actigraph wristband. This variable is reported in minutes.

Sleep Efficiency

Time frame: Two-week, real-time period of at-home activity monitoring

This variable is collected using a wearable actigraph wristband. This variable is the proportion of time-in-bed spent asleep compared to the total time spent in bed.

Sleep Onset Latency (SOL)

Time frame: Two-week, real-time period of at-home activity monitoring

This variable is collected using a wearable actigraph wristband. This variable captures how long it takes for a child to fall asleep once they are in bed.

Intra-daily Variability

Time frame: Two-week, real-time period of at-home activity monitoring

This variable is collected using a wearable actigraph wristband. Intra-daily variability is a measure of how fragmented a person's rest-activity rhythm (RAR) is over the course of a 24-hour period. quantifies the amount of switching between high and low activity levels within a day. Higher IV values indicate greater fragmentation, which can be a sign of frequent napping or inefficient sleep.

Midline Estimating Statistic of Rhythm (MESOR)

Time frame: Two-week, real-time period of at-home activity monitoring

This variable is collected using a wearable actigraph wristband. Mesor is a rhythm-adjusted mean that describes the value around which a fitted wave oscillates. The wave is dictated by the intensity of physical activity over a 24-hour period.

Functional connectivity Z-scores

Time frame: Completed during an MRI scan on Day 15

Functional connectivity will be examined among the same 6 fronto-subcortical tracts of interest including (1) OFC-limbic striatum, (2) dlPFC-executive striatum, (3) ACC-limbic striatum, (4) ACC-executive striatum, (5) OFC- and (6) ACC-amygdala in each hemisphere, as well as within- and between-network connectivity of the default mode network with the frontoparietal, salience, and affective networks. The primary measure of functional connectivity will be derived by correlating the average time series across ROIs and converting the correlations to z scores using Fisher's transform.

What is a clinical trial?

A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.

Is it safe to participate?

Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.

Will I be compensated?

Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.

Will I receive a placebo instead of treatment?

When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.

Can I leave a trial if I change my mind?

Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.

How long does a clinical trial last?

Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.