This chapter reviews postdisaster mental health problems, including posttraumatic stress disorder (PTSD), depression, prolonged grief disorder (PGD), substance abuse, and physical illness. The net result of resilience and recovery is that only a small portion of the population will manifest long-term psychological difficulties. Disasters mental health impact is expected to vary across the exposed population. While type and duration of exposure carry a lot of weight in risk for mental and physical health, additional factors, such as gender, age, disability status, and income level need to be considered. A strategic approach is needed to address the heterogeneous impact of disasters. Key challenges for treating populations in the disaster context include: early identification and intervention for individuals who are at an elevated risk for developing long-term psychological difficulties; treatment of existing mental health problems; and long-term follow up to address delayed onset and possible relapse among remitted individuals.