Prospective associations between social support and posttraumatic stress disorder may be spurious: A re-meta-analysis of longitudinal studies and a simulation

A recent meta-analysis concluded to have found proof for both a social causation model, according to which social support protects against posttraumatic stress disorder (PTSD), and a social selection model, which claims that PTSD erodes social support. However, the prospective cross-lagged effects were estimated while adjusting for a prior measurement of the outcome and this method is vulnerable for spurious findings due to correlations with residuals and regression toward the mean. The present re-analyses of the meta-analytic effects indicated that depending on used model one can choose to claim that social support has either a decreasing, an increasing, or no prospective effect on subsequent change in PTSD symptom severity, and vice versa. Therefore, claims over and above a negative cross-sectional correlation between social support and PTSD, including the social causation and social selection models, can be questioned. The findings were validated by analyses of simulated data, which indicated that prospective effects were not necessary for the observed meta-analytic associations.