The goal of this observational study is to develop and validate a clinical tool to predict which adolescents aged 11 to less than 18 years of age with mild traumatic brain injury (mTBI) are at an increased risk for developing significant new or worsening mental health conditions.

The main aims the study wish to answer are:

• Does the adolescent have new or worsening depression or anxiety defined as a change from their previous medical history using self-reported questionnaires at either one or three months post-injury?
• Does the adolescent have unmet mental health care needs, defined as not receiving any mental or behavior health care in patients with new or worsening anxiety or depression as defined by the self reported questionnaires?

Participants will be enrolled after being diagnosed in the emergency department (ED) with an mTBI. During the ED visit, the child's parent/caregiver and the adolescent will complete several questionnaires related to mental health which include tools to measure anxiety and depression. Participants will be asked to complete these questionnaires again at 1 month and 3 months post enrollment.

This is an observational, multicenter study to develop and validate a clinical tool to predict mental health problems in adolescents (after mild traumatic brain injuries (mTBI).

The primary objective of the study is to develop and validate a clinical tool to predict which adolescents with mTBIs are at an increased risk for developing significant new or worsening mental health conditions. The investigators believe that at completion of this study they will have developed and validated a clinical prediction tool that will help clinicians define adolescents with mTBIs by risk of follow up mental health complications into low, moderate, and high-risk categories. This will provide clinicians with distinct risk categories on which make decisions about an adolescents care.

The investigators will also evaluate racial, ethnic, and social and economic differences in post-mTBI management across diverse populations of adolescents with mTBIs. The investigators believe that specific racial, ethnic, social, and economical characteristics will also be associated with unmet mental health needs in adolescents with mTBIs.

Inclusion Criteria:

Children 11 to less than 18 years old who meet the Centers for Disease Control and Prevention (CDC) definition of mTBI*. In brief, this is defined as a Glasgow Coma Scale (GCS) score of 13 to 15 with:

- Head injury (e.g., direct blow or sudden deceleration/acceleration) plus any neurological sign and/or symptom such as headache, nausea, history of loss of consciousness, confusion, dizziness, amnesia (not limited to these symptoms/signs)

AND/OR

- Traumatic intracranial abnormalities on CT or MRI (such as intracranial hemorrhage, skull fracture, or diffuse axonal injury)

*mTBI is defined as an acute brain injury resulting in neurological symptoms such as confusion or disorientation, headache, nausea, loss of consciousness, amnesia, seizure, focal signs or symptoms, and/or have traumatic intracranial abnormalities on CT or MRI imaging. mTBI patients have GCS scores of 13 to 15. Per CDC precedent, we will use the term mTBI which encompasses other commonly used terms such as "concussion" or "minor head injury". This will include patients who may have neuroimaging findings of traumatic abnormalities (e.g., intracranial hemorrhage, diffuse axonal injury, skull fractures) which are risk factors for mental health problems; however, neuroimaging is not required for enrollment into the study.

Exclusion Criteria:

• Presentation to the ED >72 hours post-injury
• TBI requiring emergent neurosurgical intervention at the time of enrollment
• Other injuries requiring emergent surgery at the time of enrollment
• Parent or child unable to accurately complete the study questionnaires due to preexisting functional limitations (e.g., severe developmental delay)
• Previous known enrollment into the study
• Patient or parent does not speak English or Spanish

Participants are injured children aged 11 to 17 years old who present with a Mild traumatic brain injury (mTBI), including concussion, as defined by the Centers for Disease Control and Prevention as an acute brain injury resulting in neurological symptoms such as confusion or disorientation, loss of consciousness, amnesia, seizure, or other signs or symptoms combined with a Glasgow Coma Scale (GCS) score of 13 to 15 to one of six emergency departments (EDs) throughout the United States.