Pasalich, DaveCraig, Stephanie GGoulter, NatalieO'Donnell, Katherine AHernandez, Carlos SierraMoretti, Marlene2023-08-171537-4416http://hdl.handle.net/1885/295635Objective: Few studies have evaluated attachment-based parent interventions for pre-teens and teens, and in particular, differential adolescent trajectories of response. This study examined distinct patterns, and multi-level predictors, of intervention response among youth with serious behavioral and mental health problems whose parents participated in Connect, an attachment- and trauma-informed parent program. Method: Participants included 682 parents (M age = 42.83, 86% mothers) and 487 youth (M age = 13.95, 53% female, 28.1% ethnic minority) enrolled in a community-based evaluation of Connect. Parents and youth reported on youth externalizing and internalizing problems (EXT and INT) at six time points from baseline through 18-months post-intervention. Demographic and youth and family level predictors were assessed at baseline. Results: Growth mixture modeling revealed three distinct trajectory classes in both the parent and youth models based on different patterns of co-occurring EXT and INT and degree of improvement over time. Youth with severe EXT showed the largest and fastest improvement, and, interestingly, were characterized by higher callous-unemotional traits and risk-taking at program entry. Youth with comorbid EXT/INT demonstrated a partial or moderate response to intervention in the parent and youth model, respectively, and were characterized by more attachment anxiety at baseline. Most youth showed relatively moderate/low levels of EXT/INT at baseline which gradually improved. Caregiver strain also predicted trajectory classes. Conclusions: These results have significance for tailoring and personalizing interventions for high-risk youth and provide new understanding regarding the profiles of subgroups of youth who show different responses to an attachment-based parent intervention.This research was supported by a Canadian Institutes of Health Research Team Grant (No. 251560). Additional support for this study was provided by an Australian Research Council Discovery Early Career Researcher Award (No. DE170100078) to Dave S. Pasalich, and a Canada Research Chair (Tier 1) award to Marlene M. Moretti.application/pdfen-AU© 2021 Society of Clinical Child and Adolescent Psychology202110.1080/15374416.2021.19230222022-07-24