Prevention of Depression in At-Risk Adolescents: Moderators of Long-term Response

Abstract

In a randomized controlled trial, we found that a cognitive behavioral program (CBP) was significantly more effective than usual care (UC) in preventing the onset of depressive episodes, although not everyone benefitted from the CBP intervention. The present paper explored this heterogeneity of response. Participants were 316 adolescents (M _age = 14.8, SD = 1.4) at risk for depression due to having had a prior depressive episode or having current subsyndromal depressive symptoms and having a parent with a history of depression. Using a recursive partitioning approach to baseline characteristics, we (Weersing et al. 2016) previously had identified distinct risk clusters within conditions that predicted depressive episodes through the end of the continuation phase (month 9). The present study used the same risk clusters that had been derived in the CBP group through month 9 to reclassify the UC group and then to examine group differences in depression through month 33. We found that in this overall very high-risk sample, the CBP program was superior to UC among youth in the low-risk cluster (n = 33), characterized by higher functioning, lower anxiety, and parents not depressed at baseline, but not in the middle (n = 95) and high-risk (n = 25) clusters. Across conditions, significantly more depression-free days were found for youth in the low-risk cluster (M = 951.9, SD = 138.8) as compared to youth in the high-risk cluster (M = 800.5, SD = 226.7). Identification of moderators, based on purely prognostic indices, allows for more efficient use of resources and suggests possible prevention targets so as to increase the power of the intervention.

Keywords: Adolescents; Depression; Moderators; Prevention.

Figure 1

(a) Youths in both the low-risk CBP Cluster (red line) and the medium-risk CBP Cluster (green line) had significantly longer time to depression onset as compared to youth in the CBP high-risk Cluster (blue line). Youths in the low- and medium-risk CBP Clusters were not significantly different from each other. (b) Youths in the lower risk UC Cluster (orange line; CGAS ≥ 72.5) had significantly longer time to onset compared to youths in the higher risk UC Cluster (black line; CGAS < 72.5). The 9-month assessment was conducted at about week 41.

Figure 2

CBP youth in the low risk CBP-defined Cluster (solid line) had significantly longer time to onset compared to UC youth in the low risk CBP defined UC Cluster (dashed line). Within either the medium or high CBP-defined risk clusters, time to depression onset was not significantly different for youth in CBP (solid lines) versus UC (dashed lines). The 9-month assessment had been conducted at about week 41.