Sleep and Emotion Processing in Adolescent Post-traumatic Stress Disorder

Inclusion Criteria: All participants must meet all of the following criteria: * Aged 14-18 years old, inclusive * Must agree to inform the investigators within 48 hours of any emergent medical conditions and procedures * Able to lie still on their back for up to 1 hour * Must not be pregnant * Must agree not to participate in any other interventional clinical trials during the duration of the study * Must be willing to comply with all study procedures * Agree to have study visits video and/or audio recorded, including consent visit, clinical assessments (for staff training) and in-laboratory sleep visits (recording deleted within one month of study visit). * A primary parent or guardian is willing participate in the study and to provide informed consent * Are fluent in or predominantly speaking and reading in English In addition, PTSD and TEC youth must satisfy the following criteria: \- Must have a history of at least one traumatic event of any type, as defined by the DSM-V. This may include exposure to physical or sexual abuse, witnessing violence against loved ones or friends, traumatic accidents, natural disasters, death of a close family member etc. Additional criteria for PTSD youth: \- At baseline, meet threshold for DSM-5 criteria for current severe PTSD, as determined by the semi-structured clinical interview (KSADS). Exclusion Criteria: * Caregiver or adolescent is unwilling or unable to give adequate informed consent. * Are likely, in the investigator's opinion and via observation during the screening and clinical assessment period, to be re-exposed to their index trauma or other significant trauma, lack social support, or lack a stable living situation during study participation. * Any finding(s), based on the screening process, that the PI feels would make the study unsuitable for the participant. * Participation in the last 30 days in a clinical study involving an investigational drug * MRI contraindication * Claustrophobia or inability lie still in the scanner after practice MRI sessions. * Any participant presenting current serious suicide risk, as determined through the KSADS, responses to C-SSRS, and/or clinical judgment of the investigator, will be excluded; however, history of suicide attempts is not an exclusion. Would present a serious risk to others as established through clinical interview and contact with treating physician. * Neurodevelopmental disorders such as autism spectrum disorder * Intellectual Disability (IQ less than 70, per self-report) * Currently impaired by any medical condition that would prevent study participation * Traumatic brain injury with ongoing symptoms, including headache, visual disturbances, and/or impairments in concentration. * Neurological disorder(s) such as seizures, epilepsy, or brain tumors (Tourette's disorder, as diagnosed in the KSADS, is not exclusionary for TEC/PTSD youth) * Current use of medications or other drugs (i.e., alcohol) in a manner that may interfere with sleep. * Possible pregnancy Exclusions for Typically developing youth: * No history of or current psychopathology, as defined in the Kiddie Schedule for Affective Disorders and Schizophrenia (KSADS), with exception of past specific phobia and past, resolved episodes of depressive or anxiety disorders. Provided that: * The episode is not current (i.e. does not meet current criteria as assessed by the KSADS), * The participant is not currently receiving psychiatric treatment (medication or psychotherapy) for mood/anxiety, and * There is no current serious suicide risk (per KSADS/C-SSRS). * Current diagnosis of a sleep disorder (self-report). * Any history of any traumatic experience as defined by the DSM-V, including IPV exposure, neglect, or emotional abuse etc. PTSD Youth: \- Current diagnosis of or history of psychotic disorder, bipolar disorder, or autism spectrum disorder diagnosed by the KSADS interview. No other co-morbid disorders are exclusionary. TEC Youth: \- A current diagnosis of PTSD or a current diagnosis of or history of psychotic disorder, bipolar disorder, or autism spectrum disorder diagnosed by the KSADS interview.