Examining reciprocal influence between posttraumatic stress and depressive symptoms among natural disaster survivors

•The level of depression was antecedent to increased symptoms of PTSD.•Symptoms of PTSD was not a leading indicator of subsequent changes in the levels of depression.•Symptoms of PTSD were stable over time.•Depressive symptoms increased over time but at a slower rate as the time passed. The current study examined reciprocal effects of symptoms of posttraumatic stress disorder (PTSD) and major depressive disorder (MDD) among individuals affected by Hurricane Ike, which made landfall on September 13, 2008 Participants were 658 survivors, who participated in the Galveston Bay Recovery Study (GBRS; National Center for Disaster Mental Health Research, Galea, and Norris, 2016). Assessment was conducted at 3, 6, and 15 months after the disaster. Bivariate latent change score modeling was conducted to examine the nature of the time-sequential associations between symptoms of PTSD and MDD Results revealed a unidirectional coupling effect from depression to change in PTSD, but unidirectional coupling effect from PTSD to change in depression was not supported. Only linear relations of within-individual change and time-sequential associations between PTSD and depression were examined, and therefore, it precludes potential nonlinear relations between these constructs. Also, the results of the current study are limited to the studied timespan (i.e., 3 to 15 months). Lastly, other factors that could be confounding the change in PTSD symptoms were not examined, leaving a possibility of other constructs that may influence the change in future PTSD symptoms The current study suggests that disaster survivors with higher symptoms of depression may be at higher risk of experiencing increased PTSD symptoms even after one year, raising an importance of tailoring a treatment to alleviate depressive symptoms and to mitigate the risk of future symptoms of PTSD