Violent loss (i.e. homicide, suicide, accident) is associated with high levels of prolonged grief disorder (PGD), a condition defined as a maladaptive reaction to loss. PGD is a disorder marked by persistent yearning for the deceased, feelings of emptiness, and difficulties in accepting the loss for a period of at least six months. No meta-analytic evidence yet exists that identified specific risk factors for PGD after violent loss. Violent loss is particularly common in conflict-affected regions. Losses in warfare are often intertwined with traumatic experiences and high comorbidities between PGD and posttraumatic stress disorder (PTSD) are reported. Research has yet to determine how PGD and PTSD manifest in these populations. A further particular characteristic of violent loss in the context of warfare is the loss of a significant other to disappearance, which leaves relatives wondering about the fate of the missing person. Despite the large number of persons globally affected by the disappearance of a loved one, the scientific evidence about the psychological consequences among relatives of missing persons remains limited. This thesis followed several aims to address the above-mentioned research gaps. The first study provided a systematic review and meta-analytic evidence on risk factors for PGD among individuals exposed to a violent loss. Across 36 eligible studies (N=5911), 29 potential risk factors were identified. Large effect sizes were found for other psychological disorders, suicidality and rumination, while medium effect sizes were found for exposure to traumatic events and factors associated with the relationship to the deceased. Small effect sizes emerged for sociodemographic characteristics, multiple loss, physical symptoms and religious beliefs. Ten variables did not show a significant association with PGD. Heterogeneity was observed among several risk factors, however, subgroup analyses could not explain the heterogeneity. The meta-analysis identified, among other results, a high association between PGD and PTSD after violent loss. The second study subsequently addressed how PGD and PTSD manifest in the aftermath of warfare. The results revealed that clinical manifestations of PGD and PTSD among survivors of armed conflict may be characterized by four classes of symptom profiles: A resilient class, a PTSD class, a predominately PGD class, and a high distress class with overall high values of PGD and PTSD. Relative to the resilient class, participants in the high-distress class were more likely to be female, to have lost a close relative, to have been exposed to a higher number of traumatic events, and to perceive less social support. Compared to the PTSD class, the PGD class was marked by less time since the loss had occurred and a higher likelihood to have had lost a close relative. The third and fourth article addressed the psychological and psychosocial consequences of the loss of a significant other to disappearance by providing an overview about the current state of research (paper III) and by contributing a comparative study of relatives of disappeared persons and bereaved individuals (paper IV). The overview indicated that depression, PTSD and PGD are common consequences among relatives of disappeared persons. While three of the reviewed studies found that relatives of disappeared persons had higher levels of psychopathology than bereaved individuals, paper IV did not indicate significant differences in PGD, depression, or PTSD symptom severity between the two groups. Results of paper IV furthermore indicated that the extent to which relatives of disappeared persons hoped that their loved one was still alive was significantly associated with the severity of PGD symptoms. To conclude, prolonged grief disorder is an important psychological disorder that can emerge in response to the violent loss of a significant other. This dissertation contributes significantly to the knowledge on risk factors and clinical manifestations of PGD among violent loss survivors. This is especially relevant in the light of inclusion of PGD in the forthcoming International Classification of Diseases (ICD-11) as it will be important for clinicians to identify bereaved individuals at risk for PGD. This dissertation furthermore added important knowledge on psychological consequences and their risk factors to the under-researched field of psychological distress among relatives of disappeared persons.