New study aims to help people with disabilities suffering from uncontrollable movements

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

Participant Inclusion Criteria: * Diagnosis of IDD (IQ \< 70; social/adaptive dysfunction, onset \< age 22) as per DSM-5 * Clinical diagnosis of Tardive Dyskinesia (TD) per DSM-5 for at least 3 months before study inclusion (presence of movement disorder for at least 3 months, in absence of previous formal diagnosis of TD). * Eligible to receive deutetrabenazine, according to current product labeling Stable doses of all psychotropic medications for minimum of three months before study inclusion * Willing to remain on stable doses of all psychotropics for 24 weeks of study. If female of childbearing age, practicing acceptable form of birth control throughout study duration. * Subject able to comply with scheduled visits and assessments * Consent of subject, or legally authorized representative to study protocol. Caregiver Inclusion Criteria: * Able to understand and answer questionnaires * Able to comply with scheduled visits * Ability to be primary Caregiver for 24 weeks of study Participant Exclusion Criteria: * Previous treatment with a VMAT2 inhibitor (tetrabenazine, valbenazine, or deutetrabenazine). * Treatment with any investigational drug in the 30 days prior to study entry. * Currently taking a strong CYP2D6 inhibitor such as fluoxetine, paroxetine, quinidine, bupropion. Current treatment with strong anticholinergic agents, monoamine oxidase inhibitors, metoclopramide, dopamine agonists, L-DOPA, or stimulants within past 30 days, or botulinum toxin within the past 3 months. * Any unstable medical condition in the 60 days prior to study entry. * Pregnant or breast-feeding * Current or recent hepatic impairment * History of neuroleptic malignant syndrome * History of long QTc on electrocardiogram, bundle branch block (BBB), atrioventricular block, serious cardiac arrhythmia, or heart failure. QTc on EKG \> 450 msec (Fredericia formula) on EKG within 3 months prior to study entry. * History of substance abuse or dependence in the 3 months prior to study entry. * Significant risk of suicide or dangerous aggression to others at time of or 3 months prior to study entry. * Inability to take study medications Caregiver Exclusion Criteria: * Unable to complete questionnaires * Unable to comply with scheduled visits * Will not be a primary Caregiver for the 24 weeks of the study