We examined whether the oxytocin receptor gene (OXTR) single nucleotide polymorphism (SNP) rs53576 genotype buffers the combined impact of negative social environments (e.g., interpersonal conflict/constraint) and economic stress on post-traumatic stress (PTS) symptoms and impaired daily functioning following collective stress (September 11th terrorist attacks). Saliva was collected by mail and used to genotype 704 respondents. Participants completed Web-based assessments of pre-9/11 mental health, acute stress 9-23 days after 9/11, the quality of social environments 1 year post-9/11, economic stress 18 months post-9/11, and PTS symptoms and impaired functioning 2 and 3 years post-9/11. Interactions between negative social environments and economic stress were examined separately based on OXTR rs53576 genotype (GG vs. any A allele). For individuals with an A allele, a negative social environment significantly increased PTS symptoms without regard to the level of economic stress experienced. However, for respondents with a GG genotype, negative social environments predicted elevated PTS symptoms only for those also experiencing high economic stress. Gender moderated associations between negative social environments, economic stress, and impaired functioning. The functioning of females was most affected by negative social environments regardless of genotype and economic stress, whereas the functioning of males was differentially susceptible to economic stress depending on OXTR genotype and negative social environments. These findings suggest that it is important to consider the combined impact of gender and ongoing stress in different domains as moderators of genetic vulnerability following collective stress.

A repeat-length polymorphism of the serotonin promoter gene (5-HTTLPR) has been associated with depression and posttraumatic stress disorder (PTSD) in trauma-exposed individuals reporting unsupportive social environments. We examine the contributions of the triallelic 5-HTTLPR genotype and social constraints to posttraumatic stress (PTS) symptoms in a national sample following the September 11, 2001 (9/11) terrorist attacks. Saliva was collected by mail from 711 respondents (European American subsample n = 463) of a large national probability sample of 2,729 adults. Respondents completed web-based assessments of pre-9/11 mental and physical health, acute stress 9 to 23 days post-9/11, PTS symptoms, and social constraints on disclosure regarding fears of future terrorist attacks 2-3 years post-9/11. Social constraints were positively associated with PTS symptoms 2-3 years post-9/11. The triallelic 5-HTTLPR genotype was not directly associated with PTS symptoms, but it interacted with social constraints to predict PTS symptoms 2-3 years post-9/11: Social constraints were more strongly associated with PTS symptoms for individuals with any s/lg allele than for homozygous la/la individuals. Constraints on disclosing fears about future terrorism moderate the 5-HTTLPR genotype-PTS symptom association even when indirectly exposed to collective stress.

Transactional models of parenting and infant sleep call attention to bidirectional associations among parenting, the biosocial environment, and infant sleep behaviors. Although night waking and bedtime fussing are normative during infancy and early childhood, they can be challenging for parents. The current study, conducted in the United States between 2003 and 2009, examined concurrent and longitudinal associations between maternal mental health and infant sleep during the first year. Concurrent associations at 6 and 12 months and longitudinal associations from 6 to 12 months were studied in a non-clinic referred sample of 171 economically and culturally diverse families. Mothers with poorer mental health reported that their infants had more night waking and bedtime distress and were more bothered by these sleep issues. Associations between infant sleep and maternal mental health were moderated by culture (Hispanic/Asian vs. other) and by stressors that included high parenting stress, more stressful life events, and low family income. Individual differences in maternal well-being may color mothers' interpretations of infants' sleep behaviors. It may be prudent to intervene to support maternal mental health when infants are referred for sleep problems.