Further complicating the situation in Burundi, one of the problems people in war-affected populations often face is the high impairment due to mental health problems. Studies in crisis regions have shown that multiple experiences of traumatic life events seriously damages mental health and can lead to disorders such as Posttraumatic Stress Disorder (PTSD) or depression. Further, the risk of developing PTSD rapidly increases with the number of traumatic events experienced, as the occurrence of PTSD is more likely when the accumulation of trauma exceeds a certain limit. This phenomenon has been described as the "building block effect". This means, people in the context of armed conflicts and war are especially at risk to develop PTSD, as the total load of perceived stress is much higher than anywhere else. Furthermore, recent studies have revealed that combatants and other populations living in violent and insecure circumstances may adapt to their environment by developing an attraction to perpetrating violence, i.e. appetitive aggression. While appetitive aggression helps individuals to survive in violent environments by reducing their likelihood of developing trauma-related symptoms, it increases the risk of getting involved in the perpetration of violence.