91×ÔÅÄÂÛ̳

Research Overview

Dr. Shenk will be recruiting students to join his lab.

There are three central, interrelated aims to Dr. Shenk’s program of research:

• Improve the Estimation of Transdiagnostic Outcomes in Observational Child Maltreatment Research 

• Identify Targets Promoting Risk and Resilience to Psychopathology following Trauma 

• Optimize New and Existing Behavioral Interventions by Engaging Identified Targets

Before joining the faculty at the 91×ÔÅÄÂÛ̳ and the Mt. Hope Family Center, I was on the faculty in the Division of Behavioral Medicine and Clinical Psychology at Cincinnati Children’s Hospital Medical Center (2010-2013) as well as the Department of Human Development and Family Studies and the Department of Pediatrics at Penn State (2013-2024).

I am a board-certified clinical psychologist in clinical child and adolescent psychology and a Fellow of the American Psychological Association (Divisions 37 and 53). I am a trained provider for Trauma-Focused Cognitive-Behavioral Therapy (TF-CBT), Parent-Child Interaction Therapy (PCIT), Dialectical Behavior Therapy (DBT), and Acceptance and Commitment Therapy (ACT).

My research creates advancements for estimating, explaining, and intervening upon the onset and course of common psychiatric disorders following exposure to pediatric trauma and adversity. This research has been funded by multiple institutes at the National Institutes of Health, the National Science Foundation, the American Psychological Association, as well as other institutions and foundations.

There are three central, interrelated aims to my research that form a translational pipeline for reliably identifying intervention targets and engaging those targets more efficiently and effectively to improve transdiagnostic efforts at preventing and treating multiple, co-occurring psychiatric disorders for children exposed to trauma and adversity.

Improve the Estimation of Transdiagnostic Outcomes in Observational Child Maltreatment Research 

Much of my research has helped establish the public health effects of child maltreatment on a variety of outcomes, including substance use, psychiatric disorders, non-suicidal self-injury, and more. Conducing this research led me to ask foundational questions that currently affect our field: Why do some studies find adverse effects for child maltreatment and others don’t? Why are effect sizes for a particular outcome so different across independent studies? Should I use a substantiation indicator to create maltreatment and comparison conditions or use a self-report measure? What is the causal effect of child maltreatment? We are answering these questions by developing and testing new research design and quantitative solutions for correcting contamination bias, which occurs when children assigned to a comparison condition have been or will be exposed to maltreatment.

Our work has demonstrated that contamination is highly prevalent in child maltreatment research and biases the direction, statistical significance, and magnitude of child maltreatment effects, resulting in failures to discover and replicate those effects. We are testing these new methods using advanced quantitative approaches, such as propensity score and synthetic control models, that enhance the accuracy of child maltreatment effects by correcting both contamination bias as well as other confounding inherent in observational designs.

This research has foundations in philosophy of science, causal inference, observational designs, quantitative methods, and the measurement of child maltreatment.

Identify Targets Promoting Risk and Resilience to Psychopathology following Trauma 

Pediatric trauma affects multiple mediators and mechanisms central to the onset and course of a variety of psychiatric conditions, from cellular and physiological change, to changes in human behavior and cognition, to changes in the environment. Each of these levels of analysis need to be examined individually yet tested cumulatively if a more precise understanding of the putative causes of adverse health are to be achieved for this population.

To advance target identification for behavioral interventions, that is, knowing which factors are most critical to change to have the greatest therapeutic impact, I have been promoting research examining simultaneous changes in multiple biological and behavioral systems affected by pediatric trauma and leading to multiple forms of psychopathology. Specifically, when behavioral processes, such as avoidance and affect regulation, are tested in multivariate mediation modeling with biological processes, such as neuroendocrine, sympathetic, and parasympathetic systems, it is the behavioral processes that confer the greatest risk for or resilience to subsequent mood and trauma disorders, highlighting them putative targets for intervention.

The central roles avoidance and affect regulation play as transdiagnostic mechanisms in the pediatric trauma population has led me to research the real-time, environmental level of analysis, where we are examining caregiver-child communication patterns as potential targets for preventing psychiatric disorders following pediatric trauma. Specifically, we are modeling caregiver validating and invalidating behaviors with lag-sequential changes in child affect expressions as an active, dynamic system for reducing avoidance of trauma-related stimuli and building affect regulation capacity across multiple timescales (real-time, longitudinal) and levels of analysis (neural, affective, behavioral).

By employing this approach, where each system is examined individually and tested with other levels simultaneously, we will be able to identify critical environmental targets for intervention with direct translation across intervention platforms (prevention, treatment) for children and families affected by trauma. Core features of this research involve parent-child relationships, affect regulation observed in multiple dimensions and timescales, observational coding methods, dynamic systems modeling, and psychopathology.

Optimize New and Existing Behavioral Interventions by Engaging Identified Targets

Throughout my career, I have used experimental designs and randomized controlled trials to evaluate the effectiveness of standard behavioral interventions when applied to children with a trauma history; test the impact of individual treatment components on biological and affective mechanisms influencing behavioral health outcomes; and examine the mechanisms of action for existing, well-established treatments for trauma-related disorders. This research is offering exciting new directions for how existing interventions for the pediatric trauma population achieve their effects and the components in those interventions responsible for such change.

For example, in a randomized controlled trial where we modeled changes in the respiratory sinus arrythmia (RSA) as an index of affect regulation, we examined RSA as a potential mechanism of action for post-traumatic stress disorder (PTSD) symptom improvement during TF-CBT. This work was the first to demonstrate that TF-CBT promotes RSA withdrawal during treatment, consistent with what would be expected with exposure-based therapies. Better regulation of RSA withdrawal led to greater improvements in PTSD symptoms at post-treatment, highlighting RSA regulation as a potential mechanism of action for TF-CBT. Understanding the mechanisms of action for existing interventions, by identifying and engaging putative targets like RSA that can improve clinical outcomes, demonstrates how behavioral interventions for the pediatric trauma population work.

Such research can drive the development of new interventions that more efficiently and effectively engage those putative targets to achieve better therapeutic gains for children and their families. The foundations of this research are in experimental designs, delivery of well-established behavioral interventions for pediatric trauma and psychopathology, psychophysiology, mechanisms of action, and person-specific estimation of change.