ADHD drug trial for preschoolers pulled before it started

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Subject meets DSM-5 criteria for ADHD, combined, hyperactive/impulsive, or inattentive presentation made during a clinical interview by an experienced clinician and confirmed with the K-SADS-PL. * Subject has an age- and sex-adjusted rating of ≥90th percentile Total Score on the ADHD RS-IV Preschool Version (rated over past 6 months). * Subject has a score of ≥4 on the CGI-S at Visit 2 (Baseline). * Subject has had symptoms consistent with ADHD for at least 6 months. * Subject has a Peabody Picture Vocabulary Test, 4th edition Standard Score of ≥70 at Visit 1 (Screening Visit). * Subject has undergone an adequate course of nonpharmacological treatment for ADHD based on investigator judgment or the investigator considers the subject's condition severe enough to enroll without undergoing prior nonpharmacological treatment. Subjects who have been on a previous pharmacological treatment for ADHD may be enrolled provided they meet other entrance criteria. * Subject has participated in structured group activity (e.g., preschool, daycare, camp) for at least 1 month that in the investigator's opinion allows assessment of symptoms and impairment in a setting outside of the home. Exclusion Criteria: * Other psychiatric diagnoses * Significant cognitive impairment * Chronic medical illnesses * Structural cardiac defects * Significant abnormal lab tests * Taking disallowed medications * Subject has history of or presence at Screening of long QT syndrome or QTc greater than 450 msec at Screening (using Fridericia's formula: QTcF) or any other clinically significant 12-lead ECG abnormality. * Subject has a history of chronic vocal or motor tics or Tourette's syndrome or a family history of Tourette's syndrome. * Subject has history or presence of suicidal ideation, significant self-injurious behavior, or violent behavior. * Subject shows evidence of current physical, sexual, or emotional abuse. * Subject has a height or a weight less than or equal to the 5th percentile for age and sex at the Screening Visit. * Subject's blood pressure measurements exceed the 95th percentile for age, sex, and height at the Screening Visits (Visit 1) and/or Baseline Visit (Visit 2) per the American Academy of Pediatrics 2017 updated guidance. * Subject's biological parent has a history of bipolar disorder. * A parent/caregiver or someone living in the subject's home has a current or recent (past 12 months) history of substance abuse.