Complicated grief, also known as prolonged grief disorder, is a type of grief reaction characterized by intense and prolonged feelings of longing, sadness, and yearning for the deceased individual. Individuals experiencing complicated grief may have difficulty accepting the death, experience intrusive thoughts and memories of the deceased, and struggle to adapt to life without them. Research in complicated grief aims to better understand the factors that contribute to its development and maintenance, as well as to identify effective treatments and interventions to help individuals cope with their grief. This area of research often explores the psychological, social, and biological factors that influence the experience of complicated grief, as well as the impact of cultural and societal norms on grieving processes. Overall, the goal of research in complicated grief is to improve the support and care available to those who are struggling with the loss of a loved one.