Skip to main content
Mijn bibliotheek
Shop
Nieuws Boeken Tijdschriften E-learning Web-tv Video Audio
Tips voor Mijn BSL
UITGEBREID ZOEKEN
Inloggen
Top
Research on Child and Adolescent Psychopathology

Tip

Swipe om te navigeren naar een ander artikel

Gepubliceerd in: Journal of Abnormal Child Psychology 3/2018

09-06-2017

Applied Problem Solving in Children with ADHD: The Mediating Roles of Working Memory and Mathematical Calculation

Auteurs: Lauren M. Friedman, Mark D. Rapport, Sarah A. Orban, Samuel J. Eckrich, Catrina A. Calub

Gepubliceerd in: Research on Child and Adolescent Psychopathology | Uitgave 3/2018

Log in om toegang te krijgen
share
DELEN

Deel dit onderdeel of sectie (kopieer de link)

  • Optie A:
    Klik op de rechtermuisknop op de link en selecteer de optie “linkadres kopiëren”
  • Optie B:
    Deel de link per e-mail
    Link delen
publish
Publiceer nu

Abstract

The difficulties children with ADHD experience solving applied math problems are well documented; however, the independent and/or interactive contributions of cognitive processes underlying these difficulties are not fully understood and warrant scrutiny. The current study examines two primary cognitive processes integral to children’s ability to solve applied math problems: working memory (WM) and math calculation skills (i.e., the ability to utilize specific facts, skills, or processes related to basic math operations stored in long-term memory). Thirty-six boys with ADHD-combined presentation and 33 typically developing (TD) boys aged 8–12 years old were administered multiple counterbalanced tasks to assess upper (central executive [CE]) and lower level (phonological [PH STM] and visuospatial [VS STM] short-term memory) WM processes, and standardized measures of mathematical abilities. Bias-corrected, bootstrapped mediation analyses revealed that CE ability fully mediated between-group differences in applied problem solving whereas math calculation ability partially mediated the relation. Neither PH STM nor VS STM was a significant mediator. When modeled together via serial mediation analysis, CE in tandem with math calculation ability fully mediated the relation, explained 79% of the variance, and provided a more parsimonious explication of applied mathematical problem solving differences among children with ADHD. Results suggest that interventions designed to address applied math difficulties in children with ADHD will likely benefit from targeting basic knowledge of math facts and skills while simultaneously promoting the active interplay of these skills with CE processes.
vorige artikel Attention-Deficit Hyperactivity Disorder (ADHD) Symptoms in Children Adopted from Poland and their Atypical Association Patterns: a Bayesian Approach
volgende artikel Bending the Curve: A Community-Based Behavioral Parent Training Model to Address ADHD-Related Concerns in the Voluntary Sector in Denmark
Voetnoten
1
Studies by Rosen and Engle (1997) and others (e.g., Colom et al. 2005; Swanson and Kim 2007) provide compelling evidence that forward and backward simple digit span tasks load on a PH STM factor and are statistically separable from PH WM measures such as complex span tasks, the latter of which are more highly correlated with measures of children’s math competence.
 
2
Scores for one TD child exceeded 1.5 SDs on one of the two parents’ but not teachers’ rating scales. Parent interview revealed no significant ADHD symptoms or symptoms associated with other clinical disorders for the child. Six children with ADHD had subthreshold scores on teacher-rated hyperactivity/impulsivity. Follow-up clinical interviews, however, indicated the subthreshold symptoms were attributable to substantial psychostimulant effects while they were rated, and that all children demonstrated a history of significant, persistent levels of hyperactivity/impulsivity both at home and at school.
 
3
PH WM and VS WM performance data for a subset of the current sample were used in separate studies to evaluate conceptually unrelated hypotheses (Alderson et al. 2010, 2012; Friedman et al. 2017; Kofler et al. 2010, 2011, 2014; Raiker et al. 2012; Rapport et al. 2008, Rapport et al. 2009a, b; Sarver et al., 2015). We have not previously reported the Applied Problem Solving or Math Calculation data or their associations with our WM tasks for any children in the current sample.
 
4
SES and age were examined as potential covariates of the simple and serial mediation models presented below. Neither SES nor age were significant covariates of the model’s mediators or dependent variables, and inclusion of the covariates did not affect the pattern or interpretation of the results. Simple model results with no covariates are reported to allow B-weights to be interpreted as Cohen’s deffect sizes when predicting from a dichotomous grouping variable(Hayes 2009).
 
5
Alternative approaches were considered but not adopted because they share substantial variance with WM (e.g., the WISC-IV General Ability Index (GAI) is comprised of the Verbal Comprehension and Perceptual Reasoning Indices, and shares 25% to 40% of variance with WM).
 
Literatuur
Achenbach, T. M., & Rescorla, L. A. (2001). Manual for the ASEBA school-age forms & profiles. Burlington: University of Vermont.
Alderson, R. M., Rapport, M. D., Hudec, K. L., Sarver, D. E., & Kofler, M. J. (2010). Competing core processes in attention-deficit/hyperactivity disorder (ADHD): Do working memory deficiencies underlie behavioral inhibition deficits? Journal of Abnormal Child Psychology, 38, 497–507. CrossRefPubMed
Alderson, R. M., Rapport, M. D., Kasper, L. J., Sarver, D. E., & Kofler, M. J. (2012). Hyperactivity in boys with attention deficit/hyperactivity disorder (ADHD): The association between deficient behavioral inhibition, attentional processes, and objectively measured activity. Child Neuropsychology, 18, 487–505. CrossRefPubMed
Alderson, R. M., Kasper, L. J., Patros, C. H., Hudec, K. L., Tarle, S. J., & Lea, S. E. (2015). Working memory deficits in boys with attention deficit/hyperactivity disorder (ADHD): An examination of orthographic coding and episodic buffer processes. Child Neuropsychology, 21, 509–530. CrossRefPubMed
Alloway, T. P., Elliott, J., & Place, M. (2010). Investigating the relationship between attention and working memory in clinical and community samples. Child Neuropsychology, 16, 242–254. CrossRefPubMed
American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Arlington: American Psychiatric Publishing. CrossRef
Antonini, T. N., Kingery, K. M., Narad, M. E., Langberg, J. M., Tamm, L., & Epstein, J. N. (2016). Neurocognitive and behavioral predictors of math performance in children with and without ADHD. Journal of Attention Disorders, 20, 108–118. CrossRefPubMed
Baddeley, A. (2007). Working memory, thought, and action. New York: Oxford University Press. CrossRef
Bálint, S., Czobor, P., Komlosi, S., Meszaros, A., Simon, V., & Bitter, I. (2009). Attention deficit hyperactivity disorder (ADHD): Gender-and age-related differences in neurocognition. Psychological Medicine, 39, 1337–1345. CrossRefPubMed
Barrouillet, P., & Lépine, R. (2005). Working memory and children’s use of retrieval to solve addition problems. Journal of Experimental Child Psychology, 91, 183–204. CrossRefPubMed
Brocki, K. C., & Bohlin, G. (2004). Executive functions in children aged 6 to 13: A dimensional and developmental study. Developmental Neuropsychology, 26, 571–593. CrossRefPubMed
Brocki, K. C., & Bohlin, G. (2006). Developmental change in the relation between executive functions and symptoms of ADHD and co-occurring behaviour problems. Infant and Child Development, 15, 19–40. CrossRef
Bull, R., Johnston, R. S., & Roy, J. A. (1999). Exploring the roles of the visual-spatial sketch pad and central executive in children's arithmetical skills: Views from cognition and developmental neuropsychology. Developmental Neuropsychology, 15, 421–442. CrossRef
Cedrus Corporation (2002). SuperLab Pro (Version 2) (Computer Software). San Pedro: Cedrus Corporation.
Colom, R., Abad, F. J., Rebollo, I., & Shih, P. C. (2005). Memory span and general intelligence: A latent-variable approach. Intelligence, 33, 623–642. CrossRef
Daley, D., & Birchwood, J. (2010). ADHD and academic performance: Why does ADHD impact on academic performance and what can be done to support ADHD children in the classroom? Child: Care, Health and Development, 36, 455–464.
Dennis, M., Francis, D. J., Cirino, P. T., Schachar, R., Barnes, M. A., & Fletcher, J. M. (2009). Why IQ is not a covariate in cognitive studies of neurodevelopmental disorders. Journal of the International Neuropsychological Society, 15, 331–343. CrossRefPubMedPubMedCentral
Dirlikov, B., Rosch, K. S., Crocetti, D., Denckla, M. B., Mahone, E. M., & Mostofsky, S. H. (2015). Distinct frontal lobe morphology in girls and boys with ADHD. Neuroimage: Clinical, 7, 222–229. CrossRef
DuPaul, G. J., Gormley, M. J., & Laracy, S. D. (2013). Comorbidity of LD and ADHD: Implications of DSM-5 for assessment and treatment. Journal of Learning Disabilities, 46, 43–51. CrossRefPubMed
Engle, R. W., Tuholski, S. W., Laughlin, J. E., & Conway, A. R. (1999). Working memory, short-term memory, and general fluid intelligence: A latent-variable approach. Journal of Experimental Psychology: General, 128, 309–331. CrossRef
Epstein, J. N., Langberg, J. M., Rosen, P. J., Graham, A., Narad, M. E., Antonini, T. N., et al. (2011). Evidence for higher reaction time variability for children with ADHD on a range of cognitive tasks including reward and event rate manipulations. Neuropsychology, 25, 427–441. CrossRefPubMedPubMedCentral
Fassbender, C., Zhang, H., Buzy, W. M., Cortes, C. R., Mizuiri, D., Beckett, L., & Schweitzer, J. B. (2009). A lack of default network suppression is linked to increased distractibility in ADHD. Brain Research, 1273, 114–128. CrossRefPubMedPubMedCentral
Frazier, T. W., Youngstrom, E. A., Glutting, J. J., & Watkins, M. W. (2007). ADHD and achievement: Meta-analysis of the child, adolescent, and adult literatures and a concomitant study with college students. Journal of Learning Disabilities, 40, 49–65. CrossRefPubMed
Fried, R., Chan, J., Feinberg, L., Pope, A., Woodworth, K. Y., Faraone, S. V., & Biederman, J. (2016). Clinical correlates of working memory deficits in youth with and without ADHD: A controlled study. Journal of Clinical and Experimental Neuropsychology, 38, 487–496. CrossRefPubMedPubMedCentral
Friedman, L. M., Rapport, M. D., Raiker, J. S., Orban, S. A., & Eckrich, S. J. (2017). Reading comprehension in boys with ADHD: The mediating roles of working memory and orthographic conversion. Journal of Abnormal Child Psychology, 45, 273–287. CrossRefPubMed
Gadow, K., Sprafkin, J., Salisbury, H., Schneider, J., & Loney, J. (2004). Further validity evidence for the teacher version of the child symptom Inventory-4. School Psychology Quarterly, 19, 50–71. CrossRef
Gremillion, M. L., & Martel, M. M. (2012). Semantic language as a mechanism explaining the association between ADHD symptoms and reading and mathematics underachievement. Journal of Abnormal Child Psychology, 40, 1339–1349. CrossRefPubMedPubMedCentral
Groen, G. J., & Parkman, J. M. (1972). A chronometric analysis of simple addition. Psychological Review, 79, 329–343. CrossRef
Harvey, P. O., Le Bastard, G., Pochon, J. B., Levy, R., Allilaire, J. F., Dubois, B., & Fossati, P. (2004). Executive functions and updating of the contents of working memory in unipolar depression. Journal of Psychiatric Research, 38, 567–576. CrossRefPubMed
Hayes, A. F. (2009). Beyond baron and Kenny: Statistical mediation analysis in the new millennium. Communication Monographs, 76, 408–420. CrossRef
Hayes, A. F. (2013). Introduction to mediation, moderation, and conditional process analysis: A regression-based approach. New York: Guilford Press.
Heathcote, D. (1994). The role of visuo-spatial working memory in the mental addition of multi-digit addends. Current Psychology of Cognition, 13, 207–245.
Hollingshead, A. (1975). Four factor index of social status. New Haven: Yale University, Department of Sociology.
Insel, T. R. (2014). The NIMH research domain criteria (RDoC) project: Precision medicine for psychiatry. American Journal of Psychiatry, 171, 395–397. CrossRefPubMed
Judge, S., & Watson, S. M. (2011). Longitudinal outcomes for mathematics achievement for students with learning disabilities. The Journal of Educational Research, 104, 147–157. CrossRef
Kane, M. J., Hambrick, D. Z., Tuholski, S. W., Wilhelm, O., Payne, T. W., & Engle, R. W. (2004). The generality of working memory capacity: A latent-variable approach to verbal and visuospatial memory span and reasoning. Journal of Experimental Psychology: General, 133, 189–217. CrossRef
Karalunas, S. L., Huang-Pollock, C. L., & Nigg, J. T. (2013). Is reaction time variability in ADHD mainly at low frequencies? Journal of Child Psychology and Psychiatry, 54, 536–544. CrossRefPubMed
Kaufman, A. S., & Kaufman, N. L. (1998). Manual for the Kaufman test of educational achievement normative update (KTEA-I-NU). Circle Pines: American Guidance Service.
Kaufman, A. S., & Kaufman, N. L. (2004). Manual for the Kaufman test of educational achievement second edition (KTEA-II). Circle Pines: American Guidance Service.
Kaufman, J., Birmaher, B., Brent, D., Rao, U., Flynn, C., Moreci, P., et al. (1997). Schedule for affective disorders and schizophrenia for school-age children-present and lifetime version (K-SADS-PL): Initial reliability and validity data. Journal of the American Academy of Child and Adolescent Psychiatry, 36, 980–988. CrossRefPubMed
Kofler, M. J., Rapport, M. D., Bolden, J., Sarver, D. E., & Raiker, J. S. (2010). ADHD and working memory: The impact of central executive deficits and exceeding storage/rehearsal capacity on observed inattentive behavior. Journal of Abnormal Child Psychology, 38, 149–161. CrossRefPubMed
Kofler, M. J., Rapport, M. D., Bolden, J., Sarver, D. E., Raiker, J. S., & Alderson, R. M. (2011). Working memory deficits and social problems in children with ADHD. Journal of Abnormal Child Psychology, 39, 805–817. CrossRefPubMed
Kofler, M. J., Alderson, R. M., Raiker, J. S., Bolden, J., Sarver, D. E., & Rapport, M. D. (2014). Working memory and intraindividual variability as neurocognitive indicators in ADHD: Examining competing model predictions. Neuropsychology, 28, 459–471. CrossRefPubMed
Kuhn, J. T., Ise, E., Raddatz, J., Schwenk, C., & Dobel, C. (2016). Basic numerical processing, calculation, and working memory in children with dyscalculia and/or ADHD symptoms. Zeitschrift für Kinder-und Jugendpsychiatrie und Psychotherapie, 44, 365–375. CrossRefPubMed
Luna, B., Minshew, N. J., Garver, K. E., Lazar, N. A., Thulborn, K. R., Eddy, W. F., & Sweeney, J. A. (2002). Neocortical system abnormalities in autism: An fMRI study of spatial working memory. Neurology, 59, 834–840. CrossRefPubMed
Maguin, E., & Loeber, R. (1996). Academic performance and delinquency. Crime and Justice, 20, 145–264. CrossRef
Mathews, R. M., Whang, P. L., & Fawcett, S. B. (1982). Behavioral assessment of occupational skills of learning disabled adolescents. Journal of Learning Disabilities, 15, 38–41. CrossRefPubMed
Menon, V. (2016). Working memory in children’s math learning and its disruption in dyscalculia. Current Opinion in Behavioral Sciences, 10, 125–132. CrossRef
Metcalfe, A. W., Ashkenazi, S., Rosenberg-Lee, M., & Menon, V. (2013). Fractionating the neural correlates of individual working memory components underlying arithmetic problem solving skills in children. Developmental Cognitive Neuroscience, 6, 162–175. CrossRefPubMed
Miller, G. A., & Chapman, J. P. (2001). Misunderstanding analysis of covariance. Journal of Abnormal Psychology, 110, 40–48. CrossRefPubMed
Molina, B. S., Hinshaw, S. P., Swanson, J. M., Arnold, L. E., Vitiello, B., Jensen, P. S., et al. (2009). The MTA at 8 years: Prospective follow-up of children treated for combined-type ADHD in a multisite study. Journal of the American Academy of Child & Adolescent Psychiatry, 48, 484–500. CrossRef
Peterson, R. L., Boada, R., McGrath, L. M., Willcutt, E. G., Olson, R. K., & Pennington, B. F. (2016). Cognitive prediction of reading, math, and attention shared and unique influences. Journal of Learning Disabilities: Advanced Online Publication.
Power, T. J. (1992). Contextual factors in vigilance testing of children with ADHD. Journal of Abnormal Child Psychology, 20, 579–593. CrossRefPubMed
Raiker, J. S., Rapport, M. D., Kofler, M. J., & Sarver, D. E. (2012). Objectively-measured impulsivity and attention-deficit/hyperactivity disorder (ADHD): Testing competing predictions from the working memory and behavioral inhibition models of ADHD. Journal of Abnormal Child Psychology, 40, 699–713. CrossRefPubMed
Rapport, M. D., Alderson, R. M., Kofler, M. J., Sarver, D. E., Bolden, J., & Sims, V. (2008). Working memory deficits in boys with attention-deficit/hyperactivity disorder (ADHD): The contribution of central executive and subsystem processes. Journal of Abnormal Child Psychology, 36, 825–837. CrossRefPubMed
Rapport, M. D., Bolden, J., Kofler, M. J., Sarver, D. E., Raiker, J. S., & Alderson, R. M. (2009a). Hyperactivity in boys with attention-deficit/hyperactivity disorder (ADHD): A ubiquitous core symptom or manifestation of working memory deficits? Journal of Abnormal Child Psychology, 37, 521–534. CrossRefPubMed
Rapport, M. D., Kofler, M. J., Alderson, R. M., Timko Jr., T., & DuPaul, G. J. (2009b). Variability of attention processes in ADHD: Observations from the classroom. Journal of Attention Disorders, 12, 563–573. CrossRefPubMed
Rapport, M. D., Orban, S. A., Kofler, M. J., & Friedman, L. M. (2013). Do programs designed to train working memory, other executive functions, and attention benefit children with ADHD? A meta-analytic review of cognitive, academic, and behavioral outcomes. Clinical Psychology Review, 33, 1237–1252. CrossRefPubMed
Re, A. M., Lovero, F., Cornoldi, C., & Passolunghi, M. C. (2016). Difficulties of children with ADHD symptoms in solving mathematical problems when information must be updated. Research in Developmental Disabilities, 59, 186–193. CrossRefPubMed
Rennie, B., Beebe-Frankenberger, M., & Swanson, H. L. (2014). A longitudinal study of neuropsychological functioning and academic achievement in children with and without signs of attention-deficit/hyperactivity disorder. Journal of Clinical and Experimental Neuropsychology, 36, 621–635. CrossRefPubMed
Ritchie, S. J., & Bates, T. C. (2013). Enduring links from childhood mathematics and reading achievement to adult socioeconomic status. Psychological Science, 24, 1301–1308. CrossRefPubMed
Rogers, M., Hwang, H., Toplak, M., Weiss, M., & Tannock, R. (2011). Inattention, working memory, and academic achievement in adolescents referred for attention deficit/hyperactivity disorder (ADHD). Child Neuropsychology, 17, 444–458. CrossRefPubMed
Rosen, V. M., & Engle, R. W. (1997). Forward and backward serial recall. Intelligence, 25, 37–47. CrossRef
Sarver, D. E., Rapport, M. D., Kofler, M. J., Raiker, J. S., & Friedman, L. M. (2015). Hyperactivity in attention-deficit/hyperactivity disorder (ADHD): Impairing deficit or compensatory behavior? Journal of Abnormal Child Psychology , 43, 1219–1232.
Sarver, D. E., Rapport, M. D., Kofler, M. J., Scanlan, S. W., Raiker, J. S., Altro, T. A., & Bolden, J. (2012). Attention problems, phonological short-term memory, and visuospatial short-term memory: Differential effects on near-and long-term scholastic achievement. Learning and Individual Differences, 22, 8–19. CrossRef
Shrout, P. E., & Bolger, N. (2002). Mediation in experimental and nonexperimental studies: New procedures and recommendations. Psychological Methods, 7, 422–445. CrossRefPubMed
Simmons, F. R., Willis, C., & Adams, A. M. (2012). Different components of working memory have different relationships with different mathematical skills. Journal of Experimental Child Psychology, 111, 139–155. CrossRefPubMed
Swanson, H. L., & Fung, W. (2016). Working memory components and problem-solving accuracy: Are there multiple pathways? Journal of Educational Psychology, 108, 1153–1177. CrossRef
Swanson, H. L., & Jerman, O. (2006). Math disabilities: A selective meta-analysis of the literature. Review of Educational Research, 76, 249–274. CrossRef
Swanson, L., & Kim, K. (2007). Working memory, short-term memory, and naming speed as predictors of children's mathematical performance. Intelligence, 35, 151–168. CrossRef
Swanson, H. L., & Sachse-Lee, C. (2001). Mathematical problem solving and working memory in children with learning disabilities: Both executive and phonological processes are important. Journal of Experimental Child Psychology, 79, 294–321. CrossRefPubMed
Swanson, H. L., Jerman, O., & Zheng, X. (2008). Growth in working memory and mathematical problem solving in children at risk and not at risk for serious math difficulties. Journal of Educational Psychology, 100, 343–379. CrossRef
Tannock, R., Ickowicz, A., & Schachar, R. (1995). Differential effects of methylphenidate on working memory in ADHD children with and without comorbid anxiety. Journal of the American Academy of Child & Adolescent Psychiatry, 34, 886–896. CrossRef
Tillman, C., Eninger, L., Forssman, L., & Bohlin, G. (2011). The relation between working memory components and ADHD symptoms from a developmental perspective. Developmental Neuropsychology, 36, 181–198. CrossRefPubMed
Titz, C., & Karbach, J. (2014). Working memory and executive functions: Effects of training on academic achievement. Psychological Research, 78, 852–868. CrossRefPubMed
Van der Oord, S., Prins, P. J., Oosterlaan, J., & Emmelkamp, P. M. (2008). Efficacy of methylphenidate, psychosocial treatments and their combination in school-aged children with ADHD: A meta-analysis. Clinical Psychology Review, 28, 783–800. CrossRefPubMed
Vile Junod, R. E., DuPaul, G. J., Jitendra, A. K., Volpe, R. J., & Cleary, K. S. (2006). Classroom observations of students with and without ADHD: Differences across types of engagement. Journal of School Psychology, 44, 87–104. CrossRef
Wechsler, D. (2003). Wechsler intelligence scale for children (4th ed.). San Antonio: Psychological Corporation.
Willcutt, E. G., Doyle, A. E., Nigg, J. T., Faraone, S. V., & Pennington, B. F. (2005). Validity of the executive function theory of attention-deficit/hyperactivity disorder: A meta-analytic review. Biological Psychiatry, 57, 1336–1346. CrossRefPubMed
Williamson, D., & Johnston, C. (2015). Gender differences in adults with attention-deficit/hyperactivity disorder: A narrative review. Clinical Psychology Review, 40, 15–27. CrossRefPubMed
Zentall, S. S., & Ferkis, M. A. (1993). Mathematical problem solving for youth with ADHD, with and without learning disabilities. Learning Disability Quarterly, 16, 6–18. CrossRef
Metagegevens
Titel
Applied Problem Solving in Children with ADHD: The Mediating Roles of Working Memory and Mathematical Calculation
Auteurs
Lauren M. Friedman
Mark D. Rapport
Sarah A. Orban
Samuel J. Eckrich
Catrina A. Calub
Publicatiedatum
09-06-2017
Uitgeverij
Springer US
Gepubliceerd in
Research on Child and Adolescent Psychopathology / Uitgave 3/2018
Print ISSN: 2730-7166
Elektronisch ISSN: 2730-7174
DOI
https://doi.org/10.1007/s10802-017-0312-7

Andere artikelen Uitgave 3/2018

Journal of Abnormal Child Psychology 3/2018 Naar de uitgave

OriginalPaper

Attention-Deficit Hyperactivity Disorder (ADHD) Symptoms in Children Adopted from Poland and their Atypical Association Patterns: a Bayesian Approach

ReviewPaper

Parenting Stress through the Lens of Different Clinical Groups: a Systematic Review & Meta-Analysis

OriginalPaper

Disentangling Child-Specific and Family-Wide Processes Underlying Negative Mother-Child Transactions

OriginalPaper

Parent-Offspring Transmission of Internalizing and Sensory over-Responsivity Symptoms in Adolescence

OriginalPaper

Will Victims Become Aggressors or Vice Versa? A Cross-Lagged Analysis of School Aggression

OriginalPaper

Associations between Race and Eating Disorder Symptom Trajectories in Black and White Girls