Guanfacine Extended Release and Mindfulness Skills Therapy

Inclusion Criteria: * A lifetime history of traumatic stress documented by self and/or caregiver response on the youth self-report and or caregiver-report Structured Trauma-Related Experiences \& Symptoms Screener (STRESS) (i.e., at least one yes response on STRESS items 1-25). AND * A baseline STRESS total score ≥ 21 for females or a baseline STRESS total score ≥ 17 for males (STRESS items # 26-48: range of total scores: 0-69) 68 as completed by caregiver OR youth. AND/OR * A lifetime history of traumatic stress documented by self and/or caregiver response on the youth self-report and or caregiver-report Structured Trauma-Related Experiences \& Symptoms Screener (STRESS) (i.e., at least one yes response on STRESS items 1-25). AND * Clinically significant aggressive behavior during the preceding week assessed by a caregiver-completed Retrospective Modified Overt Aggression (R-MOAS ≥ 24).73 AND * A baseline Clinical Global Impressions-Severity Score ≥ 4.74 * Assent of child and consent of both parents/caregivers. * Living with a caregiver legally empowered to permit study enrollment and able to complete protocol assessments. * English speaking * The child is not responding to or is not tolerating well their current treatment as reported by the parent or child. * If female and reports that she is sexually active: Is willing to take a pregnancy test before study participation AND is willing to take an additional pregnancy test during the study as appropriate and necessary, and as determined by the Medical Director of the study. * Child and parent willing to give permission for the study team to contact the child's primary care physician, mental health clinician and /or mental health prescriber to communicate any changes in child's symptom status or medications as a result of participation in this research. Exclusion Criteria :• A history of cardiovascular disease, previous history of ECG abnormalities, syncope, exercise-induced cardiovascular symptoms, or any other unstable medical illness/allergy (i.e., seizure disorder) that in the opinion of the site Medical Director precludes enrollment in the study. A clinically significant history of Raynaud's disease is exclusionary. * Autistic disorder, persons with intellectual disability (IQ ≤ 70), clinically significant (in the judgment of the site Medical Director) substance abuse disorder (within the past 30 days), bipolar I disorder, schizophrenia or other psychotic disorder, or major depressive disorder with symptoms that are severe enough (e.g. suicidality) that in the opinion of the site Medical Director excludes study participation. * Concomitant Medications: Use of other psychiatric medications including extended release guanfacine (study drug) besides a stable dose of stimulants or atomoxetine for ADHD for the study duration is exclusionary for this protocol. All other medications will undergo discontinuation. * Patients who are unable to comply with the study protocol. * Females of childbearing age that are sexually active and not receiving a medically acceptable form of birth control and/or active pregnancy. * Already taking Guanfacine Extended Release