Inclusion Criteria:
* Inclusion Criteria: All Participants
1. Females of all ethnic origins See Section: Inclusion of Women and Minorities);
2. Ages 14-18 (See Section: Inclusion of Children);
3. Written informed assent/consent from adolescent and parent/guardian (if under age 18);
4. English as a first language or English fluency;
5. Right handed111;
6. Personal cell-phone (for Ecological Momentary Assessment \[EMA\]) 7 All participants will be in the follicular phase of their menstrual cycle when completing the functional magnetic resonance imaging (fMRI) study session
Inclusion Criteria: MDD Sample
1. Meet Diagnostic Statistical Manual-5th edition (DSM-5) diagnostic criteria for major depressive disorder (as diagnosed with the KSADS)
2. Absence of any psychotropic medications for at least 2 weeks (6 weeks for fluoxetine; 6 months for neuroleptics; 2 weeks for benzodiazepines; 2 weeks for any other antidepressants);
Inclusion Criteria: Healthy Control (HC) Sample
1. No history or current diagnosis of any DSM-5 psychiatric or substance/alcohol-related disorder (as diagnosed with the KSADS)
2. No first-degree relatives with a history of depression, bipolar disorder, or psychosis
Exclusion Criteria:
* Exclusion Criteria: All Participants
1. History of head trauma with loss of consciousness;
2. History of seizure disorder;
3. Serious or unstable medical illness including cardiovascular, hepatic, renal, respiratory, endocrine, neurologic or hematologic disease;
4. History of cocaine or stimulant use (e.g., amphetamine, cocaine, methamphetamine);
5. History of use of dopaminergic drugs (including methylphenidate);
6. Use of hormonal replacement therapy, anabolic steroids, or hormonal contraception;
7. Clinical or laboratory evidence of hypothyroidism;
8. Systemic medical or neurological illness that could impact fMRI measures of cerebral blood flow;
9. Failure to meet standard exclusion criteria for fMRI scanning (e.g., claustrophobia, cardiac pacemakers, neural pacemakers, surgically implanted metal devices, cochlear implants, metal braces, or other metal objects in the body);
10. Pregnancy
11. Testing positive on a drug test on the day of the scan which testis for stimulants, marijuana, barbiturates, benzodiazepine, buprenorphine, 3,4-Methyl enedioxy methamphetamine (MDMA), methadone, opiates, oxycodone, phencyclidine;
12. History of electroconvulsive therapy
13. Participants with suicidal ideation where study participation is deemed unsafe by the study clinician;
Additional Exclusion Criteria: Major Depressive Disorder (MDD) Sample
1\. Major depressive disorder diagnosis secondary to another disorder (selected comorbid anxiety disorders such as generalized anxiety disorder, specific phobia, and social anxiety disorders are allowed if they are secondary to MDD)
