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- Taylor, M. J., et al.
(författare)
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Is There a Female Protective Effect Against Attention-Deficit/Hyperactivity Disorder? Evidence From Two Representative Twin Samples
- 2016
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Ingår i: Journal of the American Academy of Child and Adolescent Psychiatry. - Stockholm : Elsevier BV. - 0890-8567 .- 1527-5418. ; 55:6, s. 504-512
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Attention-deficit/hyperactivity disorder (ADHD) is more frequent in males than in females. The "female protective effect" posits that females undergo greater exposure to etiological factors than males in order to develop ADHD, leading to the prediction that relatives of females with ADHD will display more ADHD behaviors. We thus tested whether cotwins of females displaying extreme ADHD traits would display more ADHD traits than cotwins of males displaying extreme ADHD traits. Method: Parents of approximately 7,000 pairs of nonidentical twins in Sweden, and approximately 4,000 pairs of twins in England and Wales, completed dimensional assessments of ADHD traits. Probands were selected on the basis of scoring within the highest 10% of the distribution in each sample. Dimensional scores of cotwins of probands, as well as the categorical recurrence rate, were investigated by proband sex. Results: Cotwins of female probands displayed higher mean ADHD trait scores (mean = 0.62-0.79) than cotwins of male probands (mean = 0.38-0.55) in both samples. This trend was significant in the Swedish sample (p <.01) and when the 2 samples were merged into a single, larger sample (p <.001). When the samples were merged, there was also a significant association between proband sex and cotwin's categorical status, with more cotwins of female probands also being probands than cotwins of male probands. Conclusion: These findings support a female protective effect against ADHD behaviors, suggesting that females require greater exposure to genetic and environmental factors associated with ADHD in order to develop the condition.
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| 2. |
- Ahlberg, Rickard, 1970-, et al.
(författare)
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Associations Between Attention-Deficit/Hyperactivity Disorder (ADHD), ADHD Medication and Shorter Height : A Quasi-Experimental and Family-based Study
- 2023
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Ingår i: Journal of the American Academy of Child and Adolescent Psychiatry. - : Elsevier. - 0890-8567 .- 1527-5418. ; 62:12, s. 1316-1325
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The association between attention-deficit/hyperactivity disorder (ADHD) and shorter height is unclear. This study examined the risk of shorter height in individuals with ADHD, and the influence of prenatal factors, ADHD medication, psychiatric comorbidity, socioeconomic factors and familial liability.METHOD: We draw on Swedish National Registers for two different study designs. First, height data for 14,268 individuals with ADHD and 71,339 controls were stratified into two groups: 1: Before and 2: After stimulant treatment were introduced in Sweden. Second, we used a family-based design including 833,172 relatives without ADHD with different levels of relatedness to the individuals with ADHD and matched controls.RESULTS: ADHD was associated with shorter height both before (below average height: OR=1.31, 95 % CI=1.22-1.41) and after (below average height: OR=1.21, 95 % CI=1.13-1.31) stimulants for ADHD were introduced in Sweden and was of similar magnitude in both cohorts. The association between ADHD and shorter height attenuated after adjustment for prenatal factors, psychiatric disorders and SES. Relatives of individuals with ADHD had an increased risk of shorter height (below average height in full siblings: OR=1.14, 95 % CI=1.09-1.19; maternal half siblings: OR=1.10, 95 % CI=1.01-1.20; paternal half siblings: OR=1.15, 95 % CI=1.07-1.24, first full cousins: OR=1.10, 95 % CI=1.08-1.12).CONCLUSION: Our findings suggest that ADHD is associated with shorter height. On a population level, this association was present both before and after ADHD-medications were available in Sweden. The association between ADHD and height was partly explained by prenatal factors, psychiatric comorbidity, low SES and a shared familial liability for ADHD.
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| 5. |
- Beaudry, G, et al.
(författare)
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Ms. Beaudry et al. Reply
- 2021
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Ingår i: Journal of the American Academy of Child and Adolescent Psychiatry. - : Elsevier BV. - 1527-5418 .- 0890-8567. ; 60:2, s. 203-204
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 6. |
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| 7. |
- Bolhuis, Koen, et al.
(författare)
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Disentangling Heterogeneity of Childhood Disruptive Behavior Problems Into Dimensions and Subgroups
- 2017
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Ingår i: Journal of the American Academy of Child and Adolescent Psychiatry. - : Elsevier. - 0890-8567 .- 1527-5418. ; 56:8, s. 678-686
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Irritable and oppositional behaviors are increasingly considered as distinct dimensions of oppositional defiant disorder. However, few studies have explored this multidimensionality across the broader spectrum of disruptive behavior problems (DBPs). This study examined the presence of dimensions and distinct subgroups of childhood DBPs, and the cross-sectional and longitudinal associations between these dimensions.Method: Using factor mixture models (FMMs), the presence of dimensions and subgroups of DBPs was assessed in the Generation R Study at ages 6 (n = 6,209) and 10 (n = 4,724) years. Replications were performed in two population-based cohorts (Netherlands Twin Registry, n = 4,402, and Swedish Twin Study of Child and Adolescent Development, n = 1,089) and a clinical sample (n = 1,933). We used cross-lagged modeling in the Generation R Study to assess cross-sectional and longitudinal associations between dimensions. DBPs were assessed using mother-reported responses to the Child Behavior Checklist.Results: Empirically obtained dimensions of DBPs were oppositional behavior (age 6 years), disobedient behavior, rule-breaking behavior (age 10 years), physical aggression, and irritability (both ages). FMMs suggested that one-class solutions had the best model fit for all dimensions in all three population-based cohorts. Similar results were obtained in the clinical sample. All three dimensions, including irritability, predicted subsequent physical aggression (range, 0.08-0.16).Conclusion: This study showed that childhood DBPs should be regarded as a multidimensional phenotype rather than comprising distinct subgroups. Incorporating multidimensionality will improve diagnostic accuracy and refine treatment. Future studies need to address the biological validity of the DBP dimensions observed in this study; herein lies an important opportunity for neuro-imaging and genetic measures.
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| 9. |
- Brikell, Isabell, et al.
(författare)
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Relative Immaturity in Childhood and Attention-Deficit/Hyperactivity Disorder Symptoms From Childhood to Early Adulthood : Exploring Genetic and Environmental Overlap Across Development
- 2016
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Ingår i: Journal of the American Academy of Child and Adolescent Psychiatry. - : Elsevier. - 0890-8567 .- 1527-5418. ; 55:10, s. 886-895
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Attention-deficit/hyperactivity disorder (ADHD) has been linked to immaturity relative to peers in childhood, yet it is unclear how such immaturity is associated with ADHD across development. This longitudinal twin study examined the genetic and environmental contributions to the association between parents' perception of their child's immaturity relative to peers (RI) in childhood and ADHD symptoms across development.Method: 1,302 twin pairs from the Swedish Twin Study of Child and Adolescent Development were followed prospectively from childhood to early adulthood. Parent ratings of RI were collected at 8 to 9 years and parent and self-ratings of ADHD symptoms were collected at 8 to 9, 13 to 14, 16 to 17, and 19 to 20 years using the Child Behavior Checklist Attention Problems scale. In addition, ADHD symptoms corresponding to DSM criteria were used for sensitivity analysis. Analyses were conducted using longitudinal structural equation modeling with multiple raters.Results: RI-related etiologic factors, predominantly influenced by genes, explained 10-14% of the variance in ADHD symptoms from 8 to 9 up to 16 to 17 years. The influence of these RI-related factors on ADHD symptoms attenuated to 4% by 19 to 20 years of age. The remaining variance in ADHD symptoms was primarily explained by genetic factors independent of RI, which remained relatively stable across development, explaining 19% to 30% of the variance in ADHD symptoms from 13 to 14 up to 19 to 20 years.Conclusion: The results show that RI is significantly associated with ADHD symptoms, particularly during childhood and adolescence, and that the association is primarily explained by a shared genetic liability. Nevertheless, the magnitude of associations across development was modest, highlighting that RI is merely one aspect contributing to the complex etiology of ADHD symptoms.
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| 10. |
- Cervin, Matti, et al.
(författare)
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The centrality of doubting and checking in the network structure of obsessive-compulsive symptom dimensions in youth
- 2020
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Ingår i: Journal of the American Academy of Child and Adolescent Psychiatry. - : Elsevier BV. - 0890-8567 .- 1527-5418. ; 59:7, s. 880-889
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Tidskriftsartikel (refereegranskat)abstract
- Objective. Obsessive-compulsive disorder (OCD) is a heterogeneous condition with well-established symptom dimensions across the lifespan. The objective of the present study was to use network analysis to investigate the internal structure and central features of these dimensions in unselected schoolchildren and in youth with OCD.Method. We estimated the network structure of OCD symptom dimensions in 6,991 schoolchildren and 704 youth diagnosed with OCD from 18 sites across six countries. All participants completed the Obsessive Compulsive Inventory - Child Version.Results. In both the school-based and clinic-based samples, the OCD dimensions formed an interconnected network with doubting/checking emerging as a highly central node, i.e. exerting strong influence over other symptom dimensions in the network. The centrality of the doubting/checking dimension was consistent across countries, genders, age groups, clinical status, and tic disorder comorbidity. Network differences were observed for age and gender in the school-based but not the clinic-based samples.Conclusion. The centrality of doubting/checking in the network structure of childhood OCD adds to classic and recent conceptualizations of the disorder in which the important role of doubt in disorder severity and maintenance is highlighted. The present results suggest that doubting/checking is a potentially important target for further research into the etiology and treatment of childhood OCD.
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