We don’t know with certainty, but the leading ideas are related to the idea of secondary prevention. If the unexpected trauma cannot be prevented in the first place, we hope to be able to prevent the untoward consequences of that trauma—PTSD, depression, substance abuse, and other disorders that can occur in the aftermath of trauma. What is particularly exciting about this line of research is that decades of work in the field of learning and memory have shown that new memories— even traumatic memories—are not consolidated, or made permanent, immediately. Rather, there is a period of hours to days in which potential interventions, from psychological to pharmacological, may be used to prevent the over-learning of the initial trauma memory and thus prevent PTSD and related disorders.