These are elementary, working definitions of terms. They are not intended to be exhaustive.
Trauma: Most simply defined, trauma is an experience that exceeds a person’s ability to cope. Most often, a trauma involves a fear for one’s life or a fear of annihilation in some sense. While a simple working definition is helpful, it is also important to continue to nuance one’s understanding of trauma so that not every negative or uncomfortable experience will be categorized as traumatic.
Complex Trauma: traumatic experiences that happen over an extended period of time and possibly on multiple levels. May include domestic violence, long-term child abuse, sexual abuse as well as war, extreme poverty, gun violence, forced migration, etc.
Historical & Intergenerational Trauma: traumatic experiences that occur to groups of people and continue to have long-lasting effects over multiple generations. This type of trauma includes slavery, racism, genocide, etc.
Adverse Childhood Experiences (ACEs): negative and potentially traumatic experiences that happen to children under the age of 18. According to the Centers for Disease Control and Prevention, “Adverse Childhood Experiences have been linked to risky behaviors, chronic health conditions, low life potential, and early death. As the number of ACEs increases, so does the risk for these outcomes.”
Disorder [PTSD/PTS]: Some recent scholars and mental health advocates have recommended dropping the term ‘disorder’ from PTS to emphasize the extent to which this is a natural response to trauma and, in some instances, may contribute to an individual’s ability to survive complex trauma. Developed by only about 20% of people who experience a traumatic event, PTS may include upsetting memories, intrusive thoughts, feeling on edge, trouble sleeping, avoidance, persistent feeling of threat or danger that persist for more than four months after the initial event. Symptoms also may not appear for years after an event has occurred.