The overall goal of this investigator-initiated trial is to evaluate the impact of platform algorithm products designed to rapidly identify pharmacokinetic (PK) and/or pharmacodynamic (PD) genomic variation on treatment outcome of depression in adolescents. This new technology may have the potential to optimize treatment selection by improving response, minimizing unfavorable adverse events / side effects and increasing treatment adherence

Treatment seeking adolescent patients with a moderate to severe major depressive episode defined as a 40 or greater on Childhood Depression Rating Scale-Revised (CDRS-R) will be invited to participate in this study evaluating the GeneSight® platform. This new technology can rapidly assess PK and PD genetic variation that can potentially impact antidepressant, anti-psychotic, and stimulant treatment selection. These patients will have GeneSight® testing and will be randomized to one of two groups. In Group 1 (n=138), GeneSight® testing results will be available to the patient's treating clinician prior to treatment selection. In Group 2 (n=138), testing results will not be available to the patient's research treating clinician. However, all testing results will be made available to all participants and clinicians after the 8-week trial (upon completion of blinded assessments at week 8). The patients and the clinical raters will be blinded to group assignment.

Inclusion Criteria:

• Age 13-18, male or female, any race/ethnicity
• Treating clinician, patient, and family feel that pharmacotherapy is indicated as part of a comprehensive treatment plan.
• Major depressive episode diagnosis or bipolar disorder based on KSADS-PL semi-structured psychiatric interview with a severity criteria-40 or greater on Childhood Depression Rating Scale-Revised (CDRS-R)
• Ability to provide informed consent

Exclusion Criteria:

• Inability to speak English
• Inability or lack of willingness to provide informed consent and assent.
• Axis I diagnoses: Autism Spectrum Disorder, Anorexia Nervosa, Schizophreniform, and Schizophrenia.
• Psychotropic medication change (including dosage) between screening & randomization visits.
• Patients who meet DSM 5 criteria for any significant current substance use disorder other than nicotine, caffeine, or cannabis. Must have at least early, partial or full, remission X 3 months
• Serious suicidal risk and/or in need of immediate hospitalization as judged by the investigator.
• Significant unstable medical condition.
• Anticipated inability to attend scheduled study visits.
• Patients who in the judgment of the Investigator may be unreliable or uncooperative with the evaluation procedure outlined in this protocol.
• Cytochrome (CYP) & serotonin transporter genomic testing within 5 years.