Exposed: Revealing Patterns of Community Violence Exposure and Psychological Well-Being Among Urban Youth.

Community violence exposure (CVE) is a major environmental stressor that threatens the psychological well-being of many youth living in American cities. Although research to date has documented the many psychosocial correlates of CVE among youth of all ages, issues regarding the definition and measurement of CVE limit our complete understanding of precisely how exposure to various forms of community violence relates to youths’ well-being. This study uses longitudinal data from the Project on Human Development in Chicago Neighborhoods (PHDCN) to investigate relations between CVE and both internalizing and externalizing symptoms among 4,149 youth ages 3 to 15 at baseline. In particular, this study examines patterns of emotional desensitization to CVE, the differential impact of chronic versus isolated CVE, the moderating roles of age and gender in these patterns, and the impact of CVE severity on youths’ internalizing and externalizing symptoms. Overwhelmingly, results provided support for the hypothesis that youths become emotionally desensitized to violence, as evidenced by quadratic associations between CVE and internalizing symptoms both over youths’ lifetimes and a one-year period. Quadratic associations between CVE and externalizing symptoms also emerged in some cases, but tended to be weaker than those for internalizing symptoms. Whereas linear associations were greater among older youth than younger youth, neither cohort nor gender moderated the quadratic associations between CVE and well-being. Isolated CVE was not distinctly associated with internalizing or externalizing symptoms compared with more chronic exposure, and less severe CVE was more strongly associated with well-being than more severe CVE. These findings are integrated with evidence for desensitization. Further, both theoretical and practical implications of the findings are considered, and next steps for research are offered.PHDPsychologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/99800/1/tracimk_1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99800/2/tracimk_2.pd

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Protocol for an Observational Study on the Effects of ADHD in Youth on Physical Activity

<p><strong>Background:</strong> Exercise is crucial to maintaining one's well being and has been shown to help manage the symptoms of ADHD. Sports participation in particular could be an appealing form of physical activity for youth, as sports can make exercise more enjoyable. Given the importance of exercise on the lives of youth, we seek to examine the effect of ADHD on youth engagement in physical activity and sports.</p><p><strong>Methods and Analysis:</strong> We propose a retrospective observational study comparing 647 youth with ADHD with 647 youth without ADHD. The primary outcome is frequency of physical activity. We utilize matching followed by regression-based covariance adjustment to control for potential confounders. We will also analyze the secondary outcome of youth sports participation, and plan to conduct subgroup analyses, stratified by sex and by age group, for both outcomes of interest.</p><p><strong>Keywords: Observational study, pre-analysis plan, matching, causal inference</strong></p&gt

What Happens After School? Linking Latino Adolescents Activities and Community Violence Exposure

Although community violence and the associated deleterious behavioral and psychological consequences that follow violence exposure for youth persist as serious; ongoing public health concerns; surprisingly little research has examined precursors to adolescents\u27 violence exposure. This longitudinal study investigates adolescents\u27 participation in three types of activities; specifically including home-; school-; and community-based after-school activities and examines which of these activities place youth at greater risk for experiencing community violence. The sample consists of 398 Latino high school students (53% female) with a mean age of 15.5 years (SD = 1.0) and with 85% qualifying for free and reduced school lunch. Cross-sectional results demonstrated that frequency of non-structured community-based activities and part-time work were associated with higher rates of witnessing and being victimized by violence. Adolescents\u27 endorsement of the Latino cultural value of familismo; on the other hand; was associated with lower rates of personal victimization. Longitudinal findings showed that only frequency of non-structured community-based activities was related to greater victimization and witnessing violence one year later. Our findings underscore the importance of providing structured; well supervised after-school activities for low-income youth in high-risk neighborhoods

Adult substance use as a function of growth in peer use across adolescence and young adulthood in the context of ADHD: Findings from the MTA

Peer substance use strongly predicts adolescent and young adult substance use, but its role in ADHD-related risk for substance use, especially in adulthood, is unclear. In a sample with (n = 516) and without (n = 249) childhood ADHD from the Multimodal Treatment Study of ADHD, we compared associations between change over time in peer substance use and personal substance use (alcohol, cigarettes, marijuana, illicit drugs) from age 14-26 by ADHD status. Developmentally typical peer substance use trajectories across adolescence and young adulthood coincided with similar changes in personal use - but less so for those with ADHD histories. Concurrent associations between peer and personal use in adolescence and young adulthood were weaker for those with ADHD histories than without for commonly used substances (alcohol, marijuana). Prospectively, escalating peer use during adolescence forecasted adulthood declines for commonly used substances, yet persistently high substance use at age 25, regardless of ADHD history. In the reverse direction, growth in adolescent substance use predicted developmentally normative young adult declines in peer use - but for the ADHD group, adolescent heavy drinking predicted increases in young adult peer use. Findings suggest that individuals with ADHD may have difficulty emulating their peers' developmentally normative declines in substance use, highlighting the importance of social factors when treating young adults affected by ADHD and substance abuse

Late-Onset ADHD Reconsidered With Comprehensive Repeated Assessments Between Ages 10 and 25

ObjectiveAdolescents and young adults without childhood attention deficit hyperactivity disorder (ADHD) often present to clinics seeking stimulant medication for late-onset ADHD symptoms. Recent birth-cohort studies support the notion of late-onset ADHD, but these investigations are limited by relying on screening instruments to assess ADHD, not considering alternative causes of symptoms, or failing to obtain complete psychiatric histories. The authors address these limitations by examining psychiatric assessments administered longitudinally to the local normative comparison group of the Multimodal Treatment Study of ADHD.MethodIndividuals without childhood ADHD (N=239) were administered eight assessments from comparison baseline (mean age=9.89 years) to young adulthood (mean age=24.40 years). Diagnostic procedures utilized parent, teacher, and self-reports of ADHD symptoms, impairment, substance use, and other mental disorders, with consideration of symptom context and timing.ResultsApproximately 95% of individuals who initially screened positive on symptom checklists were excluded from late-onset ADHD diagnosis. Among individuals with impairing late-onset ADHD symptoms, the most common reason for diagnostic exclusion was symptoms or impairment occurring exclusively in the context of heavy substance use. Most late-onset cases displayed onset in adolescence and an adolescence-limited presentation. There was no evidence for adult-onset ADHD independent of a complex psychiatric history.ConclusionsIndividuals seeking treatment for late-onset ADHD may be valid cases; however, more commonly, symptoms represent nonimpairing cognitive fluctuations, a comorbid disorder, or the cognitive effects of substance use. False positive late-onset ADHD cases are common without careful assessment. Clinicians should carefully assess impairment, psychiatric history, and substance use before treating potential late-onset cases

Adult substance use as a function of growth in peer use across adolescence and young adulthood in the context of ADHD: Findings from the MTA

Peer substance use strongly predicts adolescent and young adult substance use, but its role in ADHD-related risk for substance use, especially in adulthood, is unclear. In a sample with (n = 516) and without (n = 249) childhood ADHD from the Multimodal Treatment Study of ADHD, we compared associations between change over time in peer substance use and personal substance use (alcohol, cigarettes, marijuana, illicit drugs) from age 14–26 by ADHD status. Developmentally typical peer substance use trajectories across adolescence and young adulthood coincided with similar changes in personal use – but less so for those with ADHD histories. Concurrent associations between peer and personal use in adolescence and young adulthood were weaker for those with ADHD histories than without for commonly used substances (alcohol, marijuana). Prospectively, escalating peer use during adolescence forecasted adulthood declines for commonly used substances, yet persistently high substance use at age 25, regardless of ADHD history. In the reverse direction, growth in adolescent substance use predicted developmentally normative young adult declines in peer use – but for the ADHD group, adolescent heavy drinking predicted increases in young adult peer use. Findings suggest that individuals with ADHD may have difficulty emulating their peers' developmentally normative declines in substance use, highlighting the importance of social factors when treating young adults affected by ADHD and substance abuse

Cigarette Smoking Progression Among Young Adults Diagnosed With ADHD in Childhood: A 16-year Longitudinal Study of Children With and Without ADHD.

INTRODUCTION:Children with attention-deficit/hyperactivity disorder (ADHD) are at increased risk for smoking cigarettes, but there is little longitudinal research on the array of smoking characteristics known to be prognostic of long-term smoking outcomes into adulthood. These variables were studied into early adulthood in a multisite sample diagnosed with ADHD combined type at ages 7-9.9 and followed prospectively alongside an age- and sex-matched local normative comparison group (LNCG). METHODS:Cigarette smoking quantity, quit attempts, dependence, and other characteristics were assessed in the longitudinal Multimodal Treatment Study of Children with ADHD (MTA) eight times to a mean age of 24.9 years: ADHD n = 469; LNCG n = 240. RESULTS:In adulthood, the ADHD group had higher rates of daily cigarette smoking, one or more quit attempts, shorter time to first cigarette of the day, and more severe withdrawal than the LNCG. The ADHD group did not appear to have better smoking cessation rates despite a higher proportion quitting at least once. Smoking quantity and nicotine dependence did not differ between groups. The ADHD group reported younger daily smoking onset and faster progression from smoking initiation to daily smoking across assessments. Finally, ADHD symptom severity in later adolescence and adulthood was associated with higher risk for daily smoking across assessments in the ADHD sample. CONCLUSIONS:This study shows that ADHD-related smoking risk begins at a young age, progresses rapidly, and becomes resistant to cessation attempts by adulthood. Prevention efforts should acknowledge the speed of uptake; treatments should target the higher relapse risk in this vulnerable population. IMPLICATIONS:Although childhood ADHD predicts later smoking, longitudinal studies of this population have yet to fully characterize smoking behaviors into adulthood that are known to be prognostic of long-term smoking outcome. The current study demonstrates earlier and faster progression to daily smoking among those with a childhood ADHD diagnosis, as well as greater risk for failed quit attempts. Prevention efforts should address speed of smoking uptake, while treatments are needed that address smoking relapse risk. The current study also demonstrates ADHD symptom severity over development increases daily smoking risk, implicating the need for continuous ADHD symptom management