As many as 2.5 million youth per year experience homelessness. Along with losing their homes, community, friends, and routines—as well as their sense of stability and safety—many youth dealing with housing insecutiry have also experienced violence or other traumatic events. While coming from a variety of backgrounds, research suggests that most of these youth have experienced early and multiple traumas. Their responses to these events have been shaped—at least in part—by age, gender, ethnicity, and sexual orientation. This history of trauma in turn causes significant mental health problems, including depression, anxiety disorders, PTSD, suicidal ideation, attachment issues, and substance abuse disorders. Once they arrive on the street, many youths are re-traumatized. Thus, they struggle to recover from earlier traumatic events at the same time that they are trying to survive in a hostile street environment replete with countless dangers, including an increased likelihood of substance abuse and a vulnerability to being trafficked.