Unusually challenging events that have the potential to create significant human distress and can overwhelm one’s usual coping mechanisms (Volkman, 2007).

Currently defined as a catastrophic event (or series of events) in which individuals have been exposed to situations in which they were personally threatened or witnessed death, physical harm, or sexual violence (Friedman, 2015).

Trauma also includes indirect exposure in which a loved one is exposed to trauma or in which individuals repeatedly confront the consequences of trauma (e.g., body parts in warzone, mass casualty, or accident) in the line of professional duties (Friedman, 2015).