This is a non-interventional study in children and adolescents (ages 6-17 years) with attention deficit hyperactivity disorder (ADHD) to assess CNVs in specific genes involved in glutamatergic signaling and neuronal connectivity. The screening in this study will be conducted through a combination of online and site performed activities.

Inclusion Criteria:

1. Parent/legally authorized representative (LAR) can speak and read English fluently, have provided informed consent and agree to be contacted for an interventional study prior to being genotyped.
2. Subject is 6 to 17 years of age (inclusive) at the time of informed consent.
3. Parent/LAR confirms that the subject has been diagnosed with or been told by a doctor that their child has ADHD.
4. Parent/LAR confirms that the subject is not pregnant and/or breastfeeding.

Exclusion Criteria:

1. Parent/LAR confirms that the subject has been diagnosed with any of the following conditions (aside from ADHD): conduct disorder, anxiety disorder, major depression, autism spectrum disorder (ASD), bipolar disease, psychosis, hypertension, seizure disorder, syncope, or other serious cardiac problems.
2. Aside from your child's current ADHD medication (if applicable), parent/LAR confirms that the subject is currently taking any of the following medications: antidepressants, anti-anxiety medications, anti-psychotics, and/or mood stabilizers.
3. Parent/LAR confirms that the subject has been genotyped previously in the MDGN-NFC1-ADHD-001, MDGN-NFC1-ADHD-101 clinical study.

Subjects between the ages of 6 and 17 years, who have been told that they have ADHD, will be eligible for screening.