Pilot Study Evaluating the Effects of a Trust-Building Intervention on Adolescent Weight Self-Management Behaviors

Background Adolescent obesity is a serious concern in the US, placing young people at risk for multiple chronic conditions. Family-based interventions are most effective with this challenge1, but adolescents' trust of their parents diminishes around age 14 as a result of developmental brain changes2-4. This distrust may thwart family-based weight self-management interventions; therefore, in this study the investigators will assess the effects of building trust between adolescents ages 10-12 and their parents, alongside weight self-management skills. Trust is a reciprocal quality between dyads that crosses the cognitive, affective, and behavioral domains and consists of honesty, receptivity to disclosures, and perceived compatibility between one's actions and words, which results in a sense of psychological safety from criticism, embarrassment, or harm.5 Because of its central role in adolescent-parent social interactions/relationships, trust may be a key factor in acquiring and sustaining healthy behaviors. Despite literature supporting the importance of interpersonal social interactions in making behavior change1,6, no studies to date have simultaneously examined both the biological and behavioral pathways through which trust in interpersonal interactions elicits behavior change. Thus, we employ a study design that includes basic research on the role of trust as a putative intervention target for behavior change in the context of an ongoing experimental clinical study testing the effects of a family trust-building behavioral intervention designed to reduce BMI in overweight/obese adolescents. We posit that adolescent-parent trust is a unique and potentially important interpersonal communication putative target to engage behavior change to improve healthy eating, physical activity, and sleep in overweight/obese adolescents, which will in turn reduce BMI.

Research in the area of cognitive processing has identified two broad cortical neural networks, the Task Positive Network (TPN), which is involved with using skills, knowledge and self-monitoring for problem solving and goal-directed action, and the Default Mode Network (DMN), which focuses on emotion-management, self-awareness and relationships. Neural network activity is consistently observable on fMRI. These broad networks tend to be antagonistic, such that when one network is activated, the other is inhibited; this inhibition/activation of the two modes may have important implications for self-management efforts, since an individual can only efficiently adopt one mode-processing either tasks or emotions--at a given time.7,8 The Analytic v. Emotional network theory suggests that flexible and balanced activity between modes is optimal9-11 and may be modified by learning/training, including practices such as meditation.12

In the work of one of the SMART Center Core leaders 7,13, Dr. Anthony Jack, fMRI revealed that individuals, when presented with an analytical (mechanical) problem, tended to activate analytic processing while deactivating empathic (emotional) processing. Conversely, when presented with a social problem, individuals tended to deactivate the analytic processing pathways in favor of increased emotional processing. These compelling findings provide an intriguing new way to examine an individual's approach to health behaviors and provide a new view into the brain-behavior connection. Jack's work 14,15 has shown that "coaching" exerts a dose-dependent effect on brain regions associated with motivation. In particular, focused training increased activity in the ventral-medial prefrontal cortex (VMPFC in left side of Figure 2) and adjacent regions of sub-genual anterior cingulate and nucleus accumbens. These regions, which are part of the default mode network, are implicated in motivation. In addition to identifying differences in brain function and connectivity,15 we are also examining any structural changes in brain anatomy brought about by the interventions. These are hypothesized to occur in the same regions as functional changes.16,17 Prior studies have demonstrated that residual activity in the DMN, during the performance of tasks sub served by the TPN, causes errors and lapses of attention.18,19 On the other hand, the DMN plays a key role in social cognition and motivation, specifically the generation of affective meaning 15,20,21 or purpose in life. A key hypothesis is that effective tuning of DMN function is essential for effective TPN function, which is required for successful self-management. Although neural and cognitive capacities which underlie self-management behavior may be non-specific in nature, identifying key mechanisms and signatures of effective interventions will better inform theoretical frameworks of self-management science.

Significance Our premise is that self-management interventions that target both analytic and emotional components of neurocognitive processing will be most effective in helping individuals achieve self-management outcomes. We are using functional magnetic resonance imaging (fMRI) to examine the relationship between two large-scale cortical networks, the default mode network (DMN) and the task positive network (TPN), and their contributions to behavior. Numerous studies have demonstrated that these networks may suppress each other, as measured both during task performance and in the resting state, which represents a marker of psychological health 22. The investigators interpret these findings as the ability to flexibly move between distinct cognitive modes associated with each network 13. A key hypothesis is that effective tuning of DMN function is essential for effective TPN function, and in turn, optimal performance of self-management activities. We posit that the TRUST intervention will influence the adolescent's emotional (DMT) neural processing through the trust-building component, while the analytic (TPN) neural processing will be influenced by the skills building component of the intervention, both of which work together to promote healthy weight self-management behaviors 23. In addition, the investigators hypothesize that the TRUST intervention will influence the adolescent's neurological reward activation between social reward and palatable food reward demonstrated in the ventral striatum 24,25.

As demonstrated in our model-consistent with the P30 Center of Excellence in Self-Management Research (SMART) framework being used for all SMART Center studies-the investigators hypothesize that an adolescent's weight self-management behaviors are influenced by the ability of the individual to balance DMT and TPN neural processing. the investigators posit that a reduction of body mass index (BMI) and an improvement in quality of life (QOL) will result from weight self-management behaviors (eating, physical activity, sleep) as mediated by two neural processes (DMT/TPN task-switching, reward activation), adolescent trust of parent, parent trust of adolescent, adolescent/parent relationship quality, social support, decision-making, self-efficacy, patient activation, and self-regulation. The influence of potential moderators (gender, binge-eating, perceived stress, depressive symptoms, executive functioning, parenting style) will be assessed for their effect on the relationship between the intervention and the proximal and distal outcomes. The investigators will conduct a two-group intervention trial to describe the effects of the TRUST intervention on BMI, QOL, and cognitive task switching between the DMT and TPN neural networks.