Combat trauma and mid-life marital outcomes: A twin study

Marriage is considered one of the most important forms of social support that an individual receives as an adult. Although hypotheses have been formulated as to why individuals may dissolve a marriage, the determinants of marital success or failure are still relatively unknown. For the last two decades, behavioral geneticists have researched the heritability of getting married and ending a marriage by divorce; they found both marriage and divorce are, in part, genetically influenced. Epidemiologists have also studied marriage and divorce and the relationship that stress and psychopathology have with marital dissolution. In combat veterans returning from war, the role of posttraumatic stress disorder (PTSD) has been extensively investigated in its effects on marital adjustment. Individual differences, such as coping mechanisms, influence the risk of developing PTSD and there is evidence that forgiving either oneself or others may lead to decreases in symptoms that often accompany PTSD. The goals of this research are to determine the degree of genetic and environmental influences on marriage and divorce, to investigate the influence that combat has on divorce, and to determine if this relationship is mediated by PTSD or moderated by forgiveness. Participants were 4,530 twin pairs from the Vietnam Era Twin Registry. Data were obtained on marital history, combat exposure, psychopathology, and coping mechanisms. Biometrical modeling was utilized to determine the extent of genetic and environmental influences on marriage and divorce. Next, logistic regression was used to assess the relationship between combat and the two marital statuses and to test the effect of both PTSD and forgiveness in the models. Marriage and divorce both had statistically significant genetic influences that were independent of one another (i.e., different genetic factors influenced each outcome). It is likely that personality factors and various forms of psychopathology mediate the genetic influence on divorce. Combat exposure did predict divorce, but it was neither mediated by PTSD nor moderated by forgiveness. Combat has a detrimental effect on marriage as well; once the relationship between combat and marriage is better understood, clinical interventions can be tailored to address the factors that place an individual at risk for marital problems.