Systematic Review and Meta-analysis of Genetically Informed Research: Associations between Parent Anxiety and Offspring Internalizing Problems.
Ahmadzadeh YI., Schoeler T., Han M., Pingault J-B., Creswell C., McAdams TA.
OBJECTIVE: Parent anxiety is associated with offspring internalizing problems (emotional problems related to anxiety and depression). This may reflect causal processes, whereby exposure to parent anxiety directly influences offspring internalizing (and/or vice versa). However, parent-offspring associations could also be attributable to their genetic relatedness. We present a systematic review and meta-analysis to investigate whether exposure to parent anxiety is associated with offspring internalizing after controlling for genetic relatedness. METHOD: A literature search in five databases identified 429 records. Publications were retained if they used a quasi-experimental design in a general population sample to control for participant relatedness in associations between parent anxiety and offspring internalizing outcomes. Publications were excluded if they involved an experimental exposure or intervention. Studies of pre- and post-natal anxiety exposure were meta-analysed separately. Pearson's correlation coefficient estimates (r) were pooled using multilevel random effects models. RESULTS: Eight publications were retained. Data were drawn from four population cohorts, each unique to a quasi-experimental design: adoption, sibling-comparison, children-of-twins or in-vitro-fertilisation. Cohorts were located in northern Europe or America. Families were predominantly of European ancestry. Three publications (Nfamilies>11,700; offspring aged 0.5-10 years) showed no association between prenatal anxiety exposure and offspring internalizing outcomes after accounting for participant relatedness (r=.04, CI -.07,.14). Six publications (Nfamilies>12,700; offspring aged 0.75-22 years) showed a small but significant association between concurrent symptoms in parents and offspring, after accounting for participant relatedness (r=.13, CI .04,.21). CONCLUSION: Initial literature, derived from homogenous populations, suggests that prenatal anxiety exposure does not cause offspring internalizing outcomes. However, postnatal anxiety exposure may be causally associated with concurrent offspring internalizing, via non-genetic pathways. Longitudinal stability, child-to-parent effects, and the role of moderators and methodological biases require attention.