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Damme, K. S. F.

Publications and source records attributed to Damme, K. S. F..

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Lab-Based and Self-Reported Indices of Fitness Show Lowered Fitness and Insight into Fitness in Individuals at Clinical High Risk for Psychosis

IntroductionExercise is a promising intervention for clinical high-risk for psychosis (CHR) populations, who have attenuated positive symptoms, but evidence suggests that these youth may require tailored exercise interventions. Presently, the scope of the problem is unknown, as these youth may not be reliable reporters on fitness. This issue is compounded by the fact that there have been no investigations that utilized a formal fitness assessment in this critical population. The present study aims to determine the level of fitness in CHR youth with lab-based measures, test how effectively self-report measures characterize objective fitness indices, and explore clinical factors that may be interrupting reliable self-report-an important tool if these interventions are to be taken to scale. MethodsForty CHR individuals completed an exercise survey and lab-based indices of fitness (i.e., VO2max and BMI). Forty healthy volunteers completed lab indices of fitness and a structured clinical interview ruling out the presence of psychiatric illness. ResultsCHR youth showed greater BMI and lower VO2max compared to healthy volunteers. In the CHR group, abstract self-report items (perceived fitness) did not reflect lab indices of fitness, whereas specific exercise behaviors (intensity of exercise) showed stronger correlations with laboratory-based fitness measurements. Exploratory analyses suggested that positive symptoms involving grandiosity, and negative symptoms such as avolition, correlated with discrepancy between self-perception and laboratory findings of fitness. DiscussionResults suggest that CHR individuals are less objectively fit than matched controls, and that it will be important to consider unique population characteristics when weighing self-report data.

physiology

Developmental Patterning of Irritability Enhances Prediction of Psychopathology in Pre-adolescence: Improving RDoC with Developmental Science

Research has demonstrated the transdiagnostic importance of irritability in psychopathology pathways but the contribution of developmentally-unfolding patterns has only recently been explored. To address this question, irritability patterns of 110 youth from a large and diverse early childhood cohort were assessed at preschool age and at school age ([~]2.5 years later) with a dimensional irritability scale designed to capture the normal:abnormal spectrum. Participants then returned at Pre-adolescence ([~]6 years later) for an assessment with a structured clinical interview (internalizing/externalizing symptoms) and a magnetic resonance imaging scan. When only preschool age irritability was considered, this was a transdiagnostic predictor of internalizing and externalizing symptoms. However, a model including both preschool and school age irritability provided a more nuanced picture. A high preschool and decreasing school age profile of irritability predicted elevated pre-adolescence internalizing symptoms, potentially reflecting emerging coping/internalizing behavior in pre-adolescence. In contrast, a stable irritability profile across these timepoints predicted increased pre-adolescence externalizing symptoms. Further, preschool irritability (a period of rapid growth) did not predict pre-adolescent gray matter volume abnormality, an indicator of transdiagnostic clinical risk. However, irritability at school age (when gray matter volume growth is largely finished) demonstrated an interactive effect among regions; increased school age irritability predicted reduced volume in pre-adolescence emotional regions (e.g., amygdala, medial orbitofrontal cortex) and increased volume in other regions (e.g., cerebellum). Expanding the impact of RDoCs approach yielding transdiagnostic phenotypes and multiple units of analysis, a developmentally informed approach provides critical new insights into the complex unfolding of mechanisms underlying emerging psychopathology.

developmental biology