Temporal Sequence of Change in Symptoms of Anxiety and Depression in a Preventive Intervention for Children of Depressed Parents

Introduction: Anxiety and depression are important targets, both separately and conjointly, for preventive interventions with children and youth (e.g., Barrett et al., 2006). The high level of co-occurrence of these symptoms has led to the development of transdiagnostic approaches to the treatment of anxiety and depression under unified protocols (Martinsen et al., 2014). Understanding the dynamics of symptom change during and after an intervention is an important next step for intervention research in this area and may inform transdiagnostic approaches. Based on findings from Young et al. (2012), we hypothesized that greater change in anxiety symptoms in the initial phase of treatment would predict subsequent greater change in depressive symptoms.

Methods: The current study examines the effects of a family group cognitive-behavioral preventive intervention (FGCB) vs. written information (WI) control condition on symptoms of anxiety and depression in 242 offspring of parents with a history of major depressive disorder ages 9-15. Using a 3-level partially nested design, we examined whether changes in one symptom (e.g., depression) predicted later changes in the other symptom (e.g., anxiety) and vice versa in both conditions. Parents and youth completed measures of youth symptoms of anxiety and depression 5 times over a 2-year period. Parents completed the Child Behavior Checklist (CBCL) about their child, and youth completed the Youth Self Report (YSR; Achenbach & Rescorla, 2001). The Affective Problems and Anxiety Problems DSM scales were selected for analyses. The effect of rate of change symptoms of anxiety and depression on change in the alternate symptom was examined at each interval of potential change over time (0-6 months; 6-12 months; 12-18 months; 18-24 months) for both conditions.

Results: Youth in the FGCB intervention reported significantly lower symptoms than those in the WI condition on YSR Affective Problems at 6-, 12- and 18-months and YSR Anxiety Problems at 6-, 12-, and 18-months (all effects p < .05). For the FGCB condition, change in youth self-reported (β = 0.20, p < .05) and parent-reported (β = 0.23, p < .05) anxiety symptoms from 0-6 months predicted subsequent change in depressive symptoms from 6-12 months. In the WI condition, youth self-reported change in anxiety symptoms from 0-6 months predicted change in depressive symptoms from 6-12 months (β = 0.27, p < .05).  In the FGCB condition, both parent and youth reports showed that rate of initial changes in anxiety preceded and predicted changes in depressive symptoms, such that greater rate of decline in anxiety symptoms during the intervention phase predicted greater rate of decline in depressive symptoms. In the WI condition, youth report indicated that initial change in anxiety symptoms predicted a shallower increase in depressive symptoms.

Conclusions: These findings highlight the importance of initial change in symptoms of anxiety for both conditions; regardless of condition, youth were better off in the follow up phase if they show higher rates of decline in anxiety symptoms during the intervention. Further, findings suggest that targeting anxiety early in transdiagnostic interventions may improve later depressive symptom outcomes.