Bidirectional Relationship Between Intraindividual Changes in Behavioral Activation and Intraindividual Changes in Postpartum Depressive Symptoms: A Random Intercept Cross-Lagged Panel Model

According to Lewisohn's model of depression, decreases in behavioral activation (BA) occurring after facing a vital stressor may increase the risk of depression. Transition to parenthood is a potentially stressful life event that increases the risks of postpartum depression. We aimed to (a) describe the changes in BA and depressive symptomatology between the prepartum period, 1 month, 3 months, and 6 months postpartum and (b) evaluate the bidirectionality of the relationship between intraindividual changes in BA and intraindividual changes in depressive symptoms longitudinally. Chilean pregnant women (N = 503) completed a battery of questionnaires when they were between 32 and 37 weeks of gestation and 1, 3, and 6 months after delivery. A repeated measures analysis of variance showed that BA significantly decreased from prepartum to 1 month postpartum. A random intercept cross-lagged panel model supported the bidirectional inverse relationship between intraindividual changes in BA and intraindividual changes in depressive symptoms. The effect sizes of these associations were large (beta s ranging from -.141 to -.243) according to Orth et al. (2022)'s recommendations for cross-lagged effect benchmarks. This relationship showed robustness when multigroup random intercept cross-lagged panel models were conducted to adjust for several covariates (i.e., marital status, the type of health insurance, type of delivery, primiparous vs. multiparous participants, and pregnancy or delivery complication or newborn health problem). Nonetheless, reporting a previous history of major depression moderated this relationship so that intraindividual decreases in BA more likely led to intraindividual increases in depressive symptoms in people with a history of depression than in people without such a history. We discuss implications for behavioral models of depression.