| 1. |
- Isaksson, Johan, et al.
(författare)
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Evaluation of Birth Weight and Neurodevelopmental Conditions Among Monozygotic and Dizygotic Twins.
- 2023
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Ingår i: JAMA Network Open. - : American Medical Association (AMA). - 2574-3805. ; 6:6, s. e2321165-
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Tidskriftsartikel (refereegranskat)abstract
- IMPORTANCE: Low birth weight is associated with an increased likelihood of neurodivergence and neurodevelopmental conditions (NDCs) such as autism, attention-deficit/hyperactivity disorder (ADHD), and intellectual disability. However, it is unclear whether birth weight contributes independently to NDCs or whether the association is predominantly driven by genetic predisposition.OBJECTIVE: To estimate the associations between birth weight and dimensional (trait) and categorical (diagnoses) NDC outcomes, while adjusting for genetic risks.DESIGN, SETTING, AND PARTICIPANTS: A co-twin design was applied to this case-control study conducted in Sweden. Diagnostic assessments were conducted between August 2011 and March 2022, within the Roots of Autism and ADHD Twin Study in Sweden (RATSS) during a 2.5-day participant visit to the clinic. The RATSS sample comprised phenotyped monozygotic and dizygotic twins enriched for NDCs. Data analysis was conducted in November 2022.EXPOSURE: Birth weight.MAIN OUTCOMES AND MEASURES: Categorical and dimensional operationalizations of autism, ADHD, and intellectual disability were assessed. Generalized estimating equation models were fitted across and within twin pairs.RESULTS: The study sample included 393 twins: 230 were monozygotic and 159 were dizygotic (zygosity was unknown for 4). Their median age was 15 (range, 8-37) years. There were 185 female participants (47.1%) and 208 male participants (52.9%). Across twin pairs, higher birth weight was associated with fewer autistic traits (unstandardized β [B], -5.51 [95% CI, -10.09 to -0.94]) and lower odds of autism diagnosis (OR, 0.63 [95% CI, 0.45 to 0.88]) and intellectual disability (OR, 0.42 [95% CI, 0.19 to 0.92]). Within pairs, the association between birth weight and dimensional autism (B, -17.35 [95% CI, -28.66 to -6.04]) and categorical autism (OR, 0.02 [95% CI, 0.001 to 0.42]) remained among monozygotic pairs but not dizygotic pairs. In addition, higher birth weight was associated with lower odds of ADHD diagnosis (OR, 0.003 [95% CI, 0 to 0.70]), fewer ADHD traits (B, -0.25 [95% CI, -0.39 to -0.11]), and higher IQ ratings (B, 7.43 [95% CI, 1.05 to 13.82]) among monozygotic twins.CONCLUSIONS AND RELEVANCE: The findings of this co-twin study suggest an association between low birth weight and NDCs, but they also acknowledge the importance of genetics because the associations observed were only statically significant among monozygotic twins. It is of pivotal importance to facilitate early identification of factors contributing to fetal growth restriction to minimize detrimental outcomes.
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| 2. |
- Isaksson, Johan, et al.
(författare)
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Nonshared environmental factors in the aetiology of autism and other neurodevelopmental conditions : a monozygotic co-twin control study.
- 2022
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Ingår i: Molecular autism. - : Springer Nature. - 2040-2392. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: A significant proportion of variation in likelihood of neurodevelopmental conditions (NDCs) has been attributed to nonshared environmental (NSE) factors, although it remains unclear which NSE factors pose specific risks for certain NDCs.METHODS: A monozygotic co-twin design was applied in a sample of 224 twins (mean age = 17.70 years, SD = 6.28) controlling for confounders such as genes and shared environment. Generalized estimating equation models were fitted, using perinatal and postnatal indications of NSEs as exposure, operationalized both as separate risk factors and as cumulative risk loads. Categorical and dimensional operationalizations of autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), intellectual disability and other NDCs were used as outcomes.RESULTS: Birth weight discordance was associated with dimensional autism and ADHD for the smaller twin, and medication during infancy was associated with dimensional autism. Among postnatal factors scarlet fever during early childhood was associated with lower IQ. Especially autism was associated with a greater cumulative perinatal or postnatal risk load.LIMITATIONS: When exploring the associations between each condition and specific NSEs the risk of being statistically underpowered increases. Hence, we limit the reported findings on specific indicators of NSEs to trait levels and present descriptive data for categorical NDCs.CONCLUSIONS: The findings support previous research by indicating an association between exposure to perinatal and postnatal risks and subsequent NDCs within twin pairs and suggest that autism may be especially linked to accumulative early environmental risks. The findings are potentially important for developmental outcomes prognoses and may inform targeted prevention and early interventions.
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| 3. |
- Isaksson, Johan, et al.
(författare)
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Risky sexual behaviour among Russian adolescents : association with internalizing and externalizing symptoms
- 2021
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Ingår i: Child and Adolescent Psychiatry and Mental Health. - : BioMed Central. - 1753-2000. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- Background: Risky sexual behaviour (RSB) is regarded as a major health problem during adolescence. Russia has one of the highest rates of teenage pregnancy, abortion and newly diagnosed HIV infections in the world, but research on RSB in Russian youth has been limited. To address this deficit, this study examined the role of several factors, including internalizing and externalizing symptoms, in RSB among Russian adolescents. Methods: Self-reported data were collected from 2573 Russian adolescents aged 13–17 years old (59.4 % girls; Mean age = 14.89) regarding RSB (unprotected sex, early pregnancy, multiple sexual partners and substance use during sexual encounters). Information was also obtained on externalizing (conduct problems and delinquent behaviour) and internalizing (depression, anxiety and posttraumatic stress) symptoms, as well as interpersonal risk and protective factors (affiliation with delinquent peers, parental involvement and teacher support). Hierarchical multiple binary logistic regression analysis was used to examine the associations between these variables and RSB. Results: Boys reported engaging in more RSB than girls. Externalizing symptoms and affiliation with delinquent peers were most strongly associated with RSB, whereas symptoms of anxiety were negatively associated with RSB. There was an interaction effect for sex and affiliation with delinquent peers on RSB with boys reporting RSB when having more delinquent peers. Neither parental involvement nor teacher support were protective against RSB. Conclusions: Early detection of and interventions for RSB and associated externalizing symptoms may be important for adolescent physical and mental wellbeing. Affiliation with delinquent peers should, especially among boys, be regarded as a risk marker for RSB.
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| 4. |
- Isaksson, Johan, et al.
(författare)
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The danger of being inattentive – ADHD symptoms and risky sexual behaviour in Russian adolescents
- 2018
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Ingår i: European psychiatry. - : Elsevier. - 0924-9338 .- 1778-3585. ; :47, s. 42-48
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Tidskriftsartikel (refereegranskat)abstract
- AbstractBackground Prior research has indicated that attention-deficit/hyperactivity disorder (ADHD) symptoms may be associated with an increased likelihood of engaging in risky sexual behaviour (RSB). However, research on this association among adolescents has been comparatively limited and mainly confined to North America. The aim of this study was to examine if inattention and hyperactivity/impulsivity symptoms were linked to RSB in a community cohort sample of Russian adolescents. Methods The study was based on a group of 537 adolescents from Northern Russia. Information on inattention and hyperactivity/impulsivity as well as conduct problems was obtained through teacher ratings, while information on RSB (previous unprotected sex, number of sexual partners, sex while intoxicated and partner pregnancies), substance use, perception of risk, and parenting behaviour was based on students’ self-reports. Binary logistic regression analysis was used to examine associations between the variables. Results Teacher-rated inattention symptoms predicted RSB, independently of co-morbid conduct problems, substance use, risk perception, and different parenting styles (parental warmth, involvement and control). In addition, male sex, binge drinking and a lower assessment of perceived risk were all significantly associated with RSB in an adjusted model. Neither teacher-rated hyperactivity/impulsivity symptoms nor conduct problems were linked to RSB in the full model. Conclusions Deficits in planning and organizing behaviours, being easily distracted and forgetful seem to be of importance for RSB in Russian adolescents. This highlights the importance of discriminating between different types of ADHD symptoms in adolescence to prevent risk behaviours and their potentially detrimental outcomes on health and well-being.
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| 5. |
- Isaksson, Johan, et al.
(författare)
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The Role of Gender in the Associations Among Posttraumatic Stress Symptoms, Anger, and Aggression in Russian Adolescents
- 2020
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Ingår i: Journal of Traumatic Stress. - : John Wiley & Sons. - 0894-9867 .- 1573-6598. ; 33:4, s. 552-563
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Tidskriftsartikel (refereegranskat)abstract
- Symptoms of posttraumatic stress disorder (PTSD) have been linked to anger and aggressive behavior in adult and veteran populations. However, research on the associations among anger, aggression, and PTSD in adolescents is lacking, particularly regarding differences between the sexes. To address this research gap, we used self-report data from Russian adolescents (N = 2,810; age range: 13-17 years) to perform a full path analysis examining the associations between PTSD symptoms and the emotional (anger traits) and cognitive (rumination) components of anger as well as physical/verbal and social aggression, after adjusting for depressive symptoms. We also examined the interaction effects between PTSD symptoms and sex on anger and aggression. The results indicated that girls scored higher on measures of anger and PTSD symptoms, ds = 0.20-0.32, whereas boys scored higher on measures of physical and verbal aggression, d = 0.54. Clinical levels of PTSD symptoms were associated with anger rumination, β = .16, and trait anger, β = .06, and an interaction effect for PTSD symptoms and sex was found for aggression, whereby boys with clinical levels of PTSD symptoms reported more physical/verbal and social aggression, βs = .05 and .20, respectively. Our findings suggest that PTSD symptoms may have an important impact on anger, anger rumination, and aggression during adolescence. In particular, boys seem to have an increased risk for aggressive behavior in the presence of PTSD symptoms. The present results highlight the importance of taking anger and aggression into account when evaluating PTSD.
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| 6. |
- Koposov, Roman, et al.
(författare)
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Community Violence Exposure and School Functioning in Youth : Cross-Country and Gender Perspectives
- 2021
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Ingår i: Frontiers In Public Health. - : Frontiers Media S.A.. - 2296-2565. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Background: Many children and adolescents experience violent events which can be associated with negative consequences for their development, mental health, school, and social functioning. However, findings between settings and on the role of gender have been inconsistent. This study aimed to investigate cross-country and gender differences in the relationship between community violence exposure (CVE) and school functioning in a sample of youths from three countries. Methods: A self-report survey was conducted among school students (12-17 years old) in Belgium (Antwerp, N = 4,743), Russia (Arkhangelsk, N = 2,823), and the US (New Haven, N = 4,101). Students were recruited from within classes that were randomly selected from within schools that had themselves been randomly selected (excepting New Haven, where all students were included). CVE was assessed with the Screening Survey of Exposure to Community Violence. School functioning was assessed with four measures: the Perceived Teacher Support scale, Negative Classroom Environment scale, and Academic Motivation and Perception of Safety at School scales. Multivariate Analyses of Covariance were performed to assess differences in the levels of school-related problem behaviors in boys and girls, who reported different degrees of CVE. Results: Participants in all three countries reported a relatively high prevalence of violence exposure (36.2% in Belgium, 39.3% in Russia and 45.2% in the US who witnessed violence), with a higher proportion of girls than boys witnessing violent events (varied from 37.4 to 51.6% between the countries), whereas boys reported more episodes of victimization by violence than girls (varied from 32.3 to 49.9% between the countries). Youths who experienced increased CVE (from no exposure to witnessing to victimization) reported an increase in all school functioning problems in all of the countries and this association was not gender-specific. Conclusions: Our findings suggest that regardless of differences in the level of CVE by country and gender, violence exposure is negatively associated with school functioning across countries. Nonetheless, even though reactions to community violence among adolescents may be expressed in a similar fashion, cross-country differences in social support systems should also be taken into account in order to provide culturally sensitive treatment modalities.
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| 7. |
- Ruchkin, Vladislav V., 1969-, et al.
(författare)
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Prevalence and early risk factors for bulimia nervosa symptoms in inner-city youth : gender and ethnicity perspectives
- 2021
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Ingår i: Journal of Eating Disorders. - : Springer Nature. - 2050-2974. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Research on risk factors associated with bulimia nervosa symptoms (BN) in ethnic minorities has been limited. This study adds to the existing literature by providing the ethnicity- and gender-specific prevalence of BN in US inner-city youth and by exploring the longitudinal associations between a clinical level of BN and early risk factors assessed one year previously.METHODS: The study was conducted on a representative sample of predominantly ethnic minority youth (N = 2794; 54.1% female; age 11-16 years old (M(SD) = 12.77(1.29)); 60.0% African-American, 26.1% Hispanic American, 13.9% White). Self-reported information was obtained on BN and early risk factors (e.g., depressive and anxiety symptoms, posttraumatic stress, somatic complaints). Multivariate analysis of covariance was used to examine the longitudinal associations.RESULTS: The 3-month BN prevalence was higher in girls (5.1%) than in boys (2.3%) (ratio 2.22:1). Significant differences in BN rates were found between White and African American students (higher in Whites), whereas Hispanic-Americans did not differ significantly from either group. Individuals with BN had significantly higher levels of early risk factors one year prior.CONCLUSIONS: Timely recognition of BN and associated early risk factors is important for early prevention and intervention strategies.
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