How Might Differential Susceptibility Influence Complicated Grief? Ashley Harvey, Ph.D., LMFT Colorado State University Gene-environment (GxE) interactions are not typically identified as risk factors for complicated grief. However, GxE interactions are used to understand the risk of depression and PTSD, both of which can co-occur with complicated grief. One framework for GxE interaction, differential susceptibility, indicates that some individuals are genetically more sensitive to environmental experiences, both positive and negative. These persons carry more “plasticity alleles” of genes, often related to serotonin or dopamine transport, and are termed “orchids.” In contrast, “dandelions” are those who carry less plasticity alleles of genes, and are less influenced by positive or negative aspects of their environments (Boyce & Ellis, 2005). Orchids typically have the highest ratings of well-being and behavior when their environments (e.g., family relationships, social support) are supportive, and the lowest scores when their environments are unsupportive. Orchids are thus more influenced by what is happening in their lives, ‘for better or for worse’ (Belsky & Ijzendoorn, 2017). Dandelions are less reactive to environmental experiences and typically exhibit functioning in between the more extreme range of orchids. Regarding depression, for example, research by Li et al. (2013) suggests that dandelions have a low-moderate risk of depression that is less affected by either stressful life events or social support. Research on differential susceptibility has exploded in recent years: a search in PsycInfo and Medline identifies over 2,000 publications. As of yet, there are no studies investigating differential susceptibility and bereavement. However, there are studies on differential genetic risk for depression, PTSD, anxiety, and poor self-regulation in response to life stress, trauma, and social support (Boyce, 2016; Hartman & Belsky, 2015). This data can inform possible genetic and biological risk factors for complicated grief, as well as provide further evidence for the benefits of treatment and social support for more geneticallysensitive individuals. References: Belsky, J., & van Ijzendoorn, M. H. (2017). Genetic differential susceptibility to the effects of parenting. Current Opinion in Psychology, 15, 125-130. doi:10.1016/j.copsyc.2017.02.021 Boyce, W. T. (2016). Differential susceptibility of the developing brain to contextual adversity and stress. Neuropsychopharmacology, 41(1), 142-162. doi:10.1038/npp.2015.294 Boyce, W. T., & Ellis, B. J. (2005). Biological sensitivity to context: I. An evolutionary-developmental theory of the origins and functions of stress reactivity. Development and Psychopathology, 17(2), 271-301. doi:10.1017/S0954579405050145 Hartman, S., & Belsky, J. (2015). An evolutionary perspective on family studies: Differential susceptibility to environmental influences. Family Process. doi:10.1111/famp.12161 Li, J. J., Berk, M. S., & Lee, S. S. (2013). Differential susceptibility in longitudinal models of gene-environment interaction for adolescent depression. Development and Psychopathology, 25(4), 991-1003. doi:10.1017/S0954579413000321
