| 1. |
- DeYoung, Colin G., et al.
(författare)
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Variation in the catechol-O-methyltransferase Val(158)Met polymorphism associated with conduct disorder and ADHD symptoms, among adolescent male delinquents
- 2010
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Ingår i: Psychiatric Genetics. - 0955-8829 .- 1473-5873. ; 20:1, s. 20-24
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Tidskriftsartikel (refereegranskat)abstract
- Objective Variation in the catechol-O-methyltransferase gene (COMT) has been associated with antisocial behavior in populations with attention deficit/hyperactivity disorder (ADHD). This study examined whether COMT would predict antisocial behavior in a sample with high levels of behavior problems, not necessarily ADHD. In addition, because previous research suggests that COMT may be associated with ADHD in males, association between COMT and ADHD symptoms was examined. Method This study tested whether variation in three polymorphisms of the COMT gene was predictive of symptoms of conduct disorder and ADHD, in a sample of 174 incarcerated Russian adolescent male delinquents. Results The Val allele of the Val(158)Met polymorphism was significantly associated with conduct disorder diagnosis and symptoms, whereas the Met allele was associated with ADHD symptoms. Conclusion The Val(158)Met polymorphism of the COMT gene shows a complex relation to behavior problems, influencing conduct disorder and ADHD symptoms in opposite directions in a high-risk population. Psychiatr Genet 20:20-24 (C) 2010 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.
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| 2. |
- Grigorenko, Elena L., et al.
(författare)
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Aggressive behaviour, related conduct problems, and variation in genes affecting dopamine turnover
- 2010
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Ingår i: Aggressive Behavior. - : Wiley. - 0096-140X .- 1098-2337. ; 36:3, s. 158-176
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Tidskriftsartikel (refereegranskat)abstract
- A number of dopamine-related genes have been implicated in the etiology of violent behavior and conduct problems. Of these genes, the ones that code for the enzymes that influence the turnover of dopamine (DA) have received the most attention. In this study, we investigated 12 genetic polymorphisms in four genes involved with DA functioning (COMT, MAOA and MAOB, and DβH) in 179 incarcerated male Russian adolescents and two groups of matched controls: boys without criminal records referred to by their teachers as (a) “troubled-behavior-free” boys, n=182; and (b) “troubled-behavior” boys, n=60. The participants were classified as (1) being incarcerated or not, (2) having the DSM-IV diagnosis of conduct disorder (CD) or not, and (3) having committed violent or nonviolent crimes (for the incarcerated individuals only). The findings indicate that, although no single genetic variant in any of the four genes differentiated individuals in the investigated groups, various linear combinations (i.e., haplotypes) and nonlinear combinations (i.e., interactions between variants within and across genes) of genetic variants resulted in informative and robust classifications for two of the three groupings. These combinations of genetic variants differentiated individuals in incarceration vs. nonincarcerated and CD vs. no-CD groups; no informative combinations were established consistently for the grouping by crime within the incarcerated individuals. This study underscores the importance of considering multiple rather than single markers within candidate genes and their additive and interactive combinations, both with themselves and with nongenetic indicators, while attempting to understand the genetic background of such complex behaviors as serious conduct problems.
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| 3. |
- Grigorenko, Elena L., et al.
(författare)
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Exploring interactive effects on genes and environments in etiology of individual differences in reading comprehension
- 2007
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Ingår i: Development and Psychopathology. - 0954-5794 .- 1469-2198. ; 19:4, s. 1089-1103
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Tidskriftsartikel (refereegranskat)abstract
- It is established that reading and reading-related processes are heritable; genes thus play an important role in the foundation of individual differences in reading. In this article, we focus on one facet of reading–comprehension. Comprehension is a higher order cognitive skill that requires many other cognitive processes for it to unfold completely and successfully. One such process is executive functioning, which has been associated with genetic variation in the catechol-O-methyltransferase (COMT) gene. Genotypes and haplotypes of four single nucleotide polymorphisms in COMT were investigated in 179 incarcerated adolescent delinquents. Four hierarchical logistic regression models predicting the presence/absence of comprehension difficulties were fitted to the data; genetic variation in COMT and the presence/absence of maternal rejection were investigated as main effects and as effects acting interactively. Three out of four interaction terms were found to be important predictors of individual differences in comprehension. These findings were supported by the results of the haplotype analyses, in which the four investigated polymorphisms were considered simultaneously.
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| 4. |
- Haeffel, Gerald J., et al.
(författare)
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Association Between Polymorphisms in the Dopamine Transporter Gene and Depression : Evidence for a Gene-Environment Interaction in a Sample of Juvenile Detainees
- 2008
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Ingår i: Psychological Science. - : SAGE Publications. - 0956-7976 .- 1467-9280. ; 19:1, s. 62-69
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Tidskriftsartikel (refereegranskat)abstract
- Previous research has generated examples of how genetic and environmental factors can interact to create risk for psychopathology. Using a gene-by-environment (G × E) interaction design, we tested whether three polymorphisms in the dopamine transporter gene (DAT1, also referred to as SLC6A3, located at 5p15.33) interacted with maternal parenting style to predict first-onset episodes of depression. Participants were male adolescents (N= 176) recruited from a juvenile detention center in northern Russia. As hypothesized, one of the polymorphisms (rs40184) moderated the effect of perceived maternal rejection on the onset of major depressive disorder, as well as on suicidal ideation. Further, this G × E interaction was specific to depression; it did not predict clinically significant anxiety. These results highlight the need for further research investigating the moderating effects of dopaminergic genes on depression.
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| 5. |
- Hein, Sascha, et al.
(författare)
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Psychological and Sociocultural Adaptation of Children Adopted from Russia and their Associations with Pre-Adoption Risk Factors and Parenting
- 2017
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Ingår i: Journal of Child and Family Studies. - : SPRINGER. - 1062-1024 .- 1573-2843. ; 26:10, s. 2669-2680
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Tidskriftsartikel (refereegranskat)abstract
- We investigated academic and behavioral outcomes of internationally adopted children and the associations between these outcomes and age at adoption, time spent in the adoptive family, and parenting. At two time points (T1 and T2, similar to 15 months apart), we examined early academic skills (school readiness), and parent-reported behavioral adjustment (internalizing and externalizing behavior) and adaptive functioning of a sample of 75 children (45.9% boys, mean age = 5.17 years) adopted from Russia into US families. We also collected parents' self-assessments of their parenting at T1. Children who were adopted at a younger age showed higher levels of early academic skills. Correlations between age at adoption and other outcomes were overall small and mostly non-significant. However, adoptees' academic and behavioral progress differed notably in several respects. Specifically, adoptees improved in early academic skills over time, whereas, as a group, their adaptive functioning and behavioral adjustment remained stable within the normal range. Early academic skills were not related to behavioral adjustment at each time point and over time. The time spent in the adoptive family was positively related to early academic skills at T2. Whereas outcomes showed little to no relation to parenting as reported by mother and father separately, higher discrepancies between mothers' and fathers' reports of positive parenting were related to higher levels of behavioral symptoms and lower levels of adaptive skills at T2. These differential results may be explained in part by drawing upon the notion of dissociated domains of psychological and sociocultural adaptation and acculturation, outlined in the immigration literature. These results also bring to light the possible importance of between-parent consistency in parenting for adoptees' behavioral outcomes.
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| 6. |
- 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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| 7. |
- 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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| 8. |
- 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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| 9. |
- 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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| 10. |
- 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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