General Inclusion Criteria for all Adolescent Cohorts:

• Female sex assigned at birth
• Ages 13-15
• English as first language or English Fluency
• Right-handed
• Have a personal cell phone to complete the ecological momentary assessments
• Ability to give signed, informed consent/assent either written or electronic (via RedCap eConsent)
• Normal or corrected to normal vision and hearing

Additional Inclusion Criteria for Female Adolescents with a Parental History of MDD, high-risk group:

• A biological parent meeting DSM-5 criteria for at least one past/current major depressive episode

General Exclusion Criteria for all Adolescent Cohorts:

• Presence of any contraindication for MRI:

• Cardiac pacemakers
• Metal clips on blood vessels (also called stents)
• Artificial heart valve, artificial arms, hands, legs, etc.
• Brain stimulator devices
• Implanted drug pumps
• Ear or eye implants
• Known metal fragments in eyes
• Exposure to metal filings or shrapnel (sheet metal workers, welders, and others)
• Other metallic surgical hardware in vital area
• Certain tattoos with metallic ink
• Certain intrauterine devices (IUDs) containing metal
• Any other metallic objects that are deemed a contraindication to MRI that cannot be removed
• Certain transdermal (skin) patches such as:

NicoDerm (nicotine for tobacco dependence) Transderm Scop (scopolamine for motion sickness) Ortho Evra (birth control)

• Presence of medical or neurological illness that could impact fMRI measures of cerebral blood flow (e.g., head injury resulting in loss of consciousness greater than 5 minutes, seizure, tic disorder, serious/unstable cardiac, hepatic, renal, respiratory, endocrine, neurologic or hematologic illnesses)
• Clinical/Laboratory Evidence of Hypothyroidism or Hyperthyroidism
• Use of hormonal replacement therapy, anabolic steroids
• Lifetime history of electroconvulsive therapy
• Current tobacco product use
• Lifetime use of any psychotropic medication
• Clinically significant levels of depressive symptoms according to the Children's Depression Rating Scale-Revised (T Score > 54, Poznanski et al., 1996)
• Diagnosis of a neurodevelopmental disorder (e.g., Autism Spectrum Disorder, Learning Disorder w/ impairment in reading) that would interfere with study tasks (e.g., understanding and completing lengthy battery of questionnaires, ability to complete fMRI scan session and tasks without moving)

Additional Exclusion Criteria for Female Adolescents with a Parental History of MDD, high-risk group:

• Lifetime or current Diagnostic and Statistical Manual (DSM)-5 diagnoses of MDD, persistent depressive disorder, schizophrenia spectrum or other psychotic disorder, bipolar disorder, substance/alcohol use disorder, eating disorders, and posttraumatic stress disorder

Additional Exclusion Criteria for Female Adolescents without a Parental History of MDD, low-risk group:

• Any past or current Diagnostic and Statistical Manual (DSM)-5 psychiatric or substance/alcohol use disorder
• First-degree relative history of any psychiatric disorder