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Background: Depressed mood is prevalent during pregnancy, with accumulating evidence suggesting an impact on developmental outcome in the offspring. However, the long-term effects of prenatal maternal depression regarding internalizing psychopathology in the offspring are as yet unclear. Results: In n=85 young adults exposed to prenatal maternal depressed mood, no significantly higher risk for a diagnosis of depressive disorder was observed. However, they reported significantly lower levels of depressive symptoms. This association was especially pronounced when prenatal maternal depressed mood was present during the first trimester of pregnancy and when maternal mood was depressed pre- as well as postnatally. At an uncorrected level only, prenatal maternal depressed mood was associated with decreased amygdala volume. Limitations: Prenatal maternal depressed mood was not assessed during pregnancy, but shortly after childbirth. No diagnoses of maternal clinical depression during pregnancy were available. Conclusions: Self-reported depressive symptoms do not imply increased, but rather decreased symptom levels in young adults who were exposed to prenatal maternal depressed mood. A long-term perspective may be important when considering consequences of prenatal risk factors.
ResultsUnder conditions of elevated prenatal maternal stress, children carrying one or two DRD4 7r alleles were at increased risk of a diagnosis of CD/ODD. Moreover, homozygous carriers of the DRD4 7r allele displayed more externalizing behavior following exposure to higher levels of prenatal maternal stress, while homozygous carriers of the DRD4 4r allele turned out to be insensitive to the effects of prenatal stress.
ConclusionsThis study is the first to report a gene-environment interaction related to DRD4 and prenatal maternal stress using data from a prospective study, which extends earlier findings on the impact of prenatal maternal stress with respect to childhood antisocial behavior.
Background: Cannabis is the most commonly used illegal substance among adolescents and young adults. Problematic cannabis use is often associated with comorbid psychopathological problems. The purpose of the current study was to elucidate the underlying developmental processes connecting externalizing and internalizing psychopathology in childhood and adolescence with problematic cannabis use in young adulthood. Methods: Data were drawn from the Mannheim Study of Children at Risk, an ongoing epidemiological cohort study from birth to adulthood. For n = 307 participants, symptom scores of conduct/oppositional defiant disorder, attention problems, hyperactivity/impulsivity, and internalizing disorders were available for the periods of childhood (4.5-11 years) and adolescence (15 years). At age 25 years, problematic cannabis use was assessed via clinical interview and a self-rating questionnaire. Results: At age 25 years, problematic cannabis use was identified in n = 28 participants (9.1%). Childhood conduct/oppositional behavior problems were predictive of problematic cannabis use during young adulthood when comorbid symptoms were controlled for. No such effect was found for childhood attention, hyperactivity/impulsivity or internalizing problems. With respect to psychopathological symptoms during adolescence, only attention problems were significantly related to later problematic cannabis use when controlling for comorbidity. Conclusions: The current study highlights the role of conduct/oppositional behavior problems during childhood and attention problems during adolescence in later problematic cannabis use. It sheds more light on the developmental sequence of childhood and adolescence psychopathology and young adult cannabis use, which is a prerequisite for effective prevention approaches. (C) 2016 Elsevier Ireland Ltd. All rights reserved.
Interindividual variability in the regulation of the human stress system accounts for a part of the individual's liability to stress-related diseases. These differences are influenced by environmental and genetic factors. Early childhood adversity is a well-studied environmental factor affecting an individual's stress response which has been shown to be modulated by gene environment interaction (GxE). Neuropeptide Y (NPY) plays a role in stress regulation and genetic variation in NPY may influence stress responses. In this study, we analyzed the association of a common variant in the NPY gene promoter, rs16147, with cortisol and ACTH responses to acute psychosocial stress in young adults from the Mannheim Study of Children at Risk (MARS), an ongoing epidemiological cohort study following the outcome of early adversity from birth into adulthood. We found evidence of a GxE interaction between rs16147 and early adversity significantly affecting HPA axis responses to acute psychosocial stress. These findings suggest that the neurobiological mechanisms linking early adverse experience and later neuroendocrine stress regulation are modulated by a gene variant whose functional relevance is documented by increasing convergent evidence from in vitro, animal and human studies.
Lower P300 amplitude in eight-year-old offspring of alcoholic fathers with a delinquent history
(2006)
The aim of the present study was to investigate the P300 amplitude as a possible vulnerability marker in children of alcoholic (COA) fathers with and without paternal delinquency. Event-related potentials (ERPs) of 122 children aged 8 years (63 boys, 59 girls) were compared depending on father's alcoholism subtype: 30 COAs without paternal delinquency, 10 COAs with paternal delinquency, and 82 children of non-alcoholic and non-delinquent fathers. ERPs were recorded from Fz, Cz, and Pz, using an auditory oddball paradigm. Sinus tones of 60 dB HL were presented binaurally at 1,000 Hz (standard stimulus) and 2,000 Hz (target stimulus), at a relative frequency ratio of 80:20. Two trial blocks of 250 stimuli each were collected. Results indicated that only COAs with paternal delinquency displayed significant differences from the control group, characterized by reduced P300 amplitude at frontal site and in the second trial block. Thus, the combination of fathers' alcoholism and delinquency was more likely to relate to attenuated P300 amplitude in the offspring than paternal alcoholism alone. Our results suggest that both alcoholic and delinquent family history appear to play a role in P300 amplitude reduction in the offspring.
In crop modeling and yield predictions, the heterogeneity of agricultural landscapes is usually not accounted for. This heterogeneity often arises from landscape elements like forests, hedges, or single trees and shrubs that cast shadows. Shading from forested areas or shrubs has effects on transpiration, temperature, and soil moisture, all of which affect the crop yield in the adjacent arable land. Transitional gradients of solar irradiance can be described as a function of the distance to the zero line (edge), the cardinal direction, and the height of trees. The magnitude of yield reduction in transition zones is highly influenced by solar irradiance-a factor that is not yet implemented in crop growth models on a landscape level. We present a spatially explicit model for shading caused by forested areas, in agricultural landscapes. With increasing distance to forest, solar irradiance and yield increase. Our model predicts that the shading effect from the forested areas occurs up to 15 m from the forest edge, for the simulated wheat yields, and up to 30 m, for simulated maize. Moreover, we estimated the spatial extent of transition zones, to calculate the regional yield reduction caused by shading of the forest edges, which amounted to 5% to 8% in an exemplary region.
Human-driven fragmentation of landscapes leads to the formation of transition zones between ecosystems that are characterised by fluxes of matter, energy and information. These transition zones may offer rather inhospitable habitats that could jeopardise biodiversity. On the other hand, transition zones are also reported to be hotspots for biodiversity and even evolutionary processes. The general mechanisms and influence of processes in transition zones are poorly understood. Although heterogeneity and diversity of land use of fragments and the transition zones between them play an important role, most studies only refer to forested transition zones. Often, only an extrapolation of measurements in the different fragments themselves is reported to determine gradients in transition zones. This paper contributes to a quantitative understanding of agricultural landscapes beyond individual ecotopes, and towards connected ecosystem mosaics that may be beneficial for the provision of ecosystem services.
Fragmentation of landscapes creates a transition zone in between natural habitats or different kinds of land use. In forested and agricultural landscapes with transition zones, microclimate and matter cycling are markedly altered. This probably accelerates and is intensified by global warming. However, there is no consensus on defining transition zones and quantifying relevant variables for microclimate and matter cycling across disciplines. This article is an attempt to a) revise definitions and offer a framework for quantitative ecologists, b) review the literature on microclimate and matter cycling in transition zones and c) summarise this information using meta-analysis to better understand bio-geochemical and bio-geophysical processes and their spatial extent in transition zones. We expect altered conditions in soils of transition zones to be 10-20 m with a maximum of 50 m, and 25-50 m for above-ground space with a maximum of 125 m.
For millennia, humans have affected landscapes all over the world. Due to horizontal expansion, agriculture plays a major role in the process of fragmentation. This process is caused by a substitution of natural habitats by agricultural land leading to agricultural landscapes. These landscapes are characterized by an alternation of agriculture and other land use like forests. In addition, there are landscape elements of natural origin like small water bodies. Areas of different land use are beside each other like patches, or fragments. They are physically distinguishable which makes them look like a patchwork from an aerial perspective. These fragments are each an own ecosystem with conditions and properties that differ from their adjacent fragments. As open systems, they are in exchange of information, matter and energy across their boundaries. These boundary areas are called transition zones. Here, the habitat properties and environmental conditions are altered compared to the interior of the fragments. This changes the abundance and the composition of species in the transition zones, which in turn has a feedback effect on the environmental conditions.
The literature mainly offers information and insights on species abundance and composition in forested transition zones. Abiotic effects, the gradual changes in energy and matter, received less attention. In addition, little is known about non-forested transition zones. For example, the effects on agricultural yield in transition zones of an altered microclimate, matter dynamics or different light regimes are hardly researched or understood. The processes in transition zones are closely connected with altered provisioning and regulating ecosystem services. To disentangle the mechanisms and to upscale the effects, models can be used.
My thesis provides insights into these topics: literature was reviewed and a conceptual framework for the quantitative description of gradients of matter and energy in transition zones was introduced. The results of measurements of environmental gradients like microclimate, aboveground biomass and soil carbon and nitrogen content are presented that span from within the forest into arable land. Both the measurements and the literature review could not validate a transition zone of 100 m for abiotic effects. Although this value is often reported and used in the literature, it is likely to be smaller.
Further, the measurements suggest that on the one hand trees in transition zones are smaller compared to those in the interior of the fragments, while on the other hand less biomass was measured in the arable lands’ transition zone. These results support the hypothesis that less carbon is stored in the aboveground biomass in transition zones. The soil at the edge (zero line) between adjacent forest and arable land contains more nitrogen and carbon content compared to the interior of the fragments. One-year measurements in the transition zone also provided evidence that microclimate is different compared to the fragments’ interior.
To predict the possible yield decreases that transition zones might cause, a modelling approach was developed. Using a small virtual landscape, I modelled the effect of a forest fragment shading the adjacent arable land and the effects of this on yield using the MONICA crop growth model. In the transition zone yield was less compared to the interior due to shading. The results of the simulations were upscaled to the landscape level and exemplarily calculated for the arable land of a whole region in Brandenburg, Germany.
The major findings of my thesis are: (1) Transition zones are likely to be much smaller than assumed in the scientific literature; (2) transition zones aren’t solely a phenomenon of forested ecosystems, but significantly extend into arable land as well; (3) empirical and modelling results show that transition zones encompass biotic and abiotic changes that are likely to be important to a variety of agricultural landscape ecosystem services.
Aims: To investigate whether concurrent alcohol and tobacco use during early adolescence characterizes a subgroup that differs from users of one substance only regarding several risk factors for later substance use problems. Methods: Participants were from a prospective longitudinal cohort study of 384 children at risk for later psychopathology, with the majority being born with obstetric complications and psychosocial adversities. Assessments of adolescent drug consumption and related intrapersonal characteristics were obtained at age 15. Results: Compared to consumers of alcohol only, 15-year-olds drinking and smoking during the same time period (past 4 weeks) had significantly higher levels of consumption and more excessive use of alcohol, started drinking at an earlier age, had higher scores on the Fagerstrom Test for Nicotine Dependence, and more cannabis use. This group could be distinguished from users of alcohol only by higher novelty seeking and more positive alcohol effect expectancies. Compared to consumers of tobacco only, concurrent users reported higher nicotine dependence and more cannabis use. No significant differences were observed regarding frequency and age at initiation of tobacco use, tobacco-related sensitivity, self- efficacy and instrumentality as well as novelty seeking. Conclusions: Concurrent alcohol and tobacco use during early adolescence is associated with characteristics that are well known as risk factors for later alcohol use problems and dependence and that should be targeted by prevention programs.
Maternal stimulation in infancy predicts hypothalamic-pituitary-adrenal axis reactivity in young men
(2013)
Evidence from animal research has demonstrated the effect of early maternal care on the offspring's endocrine and behavioral stress response in adulthood. The present prospective study investigates, in humans, the long-term impact of maternal responsiveness and stimulation during early mother-child interaction on adrenocorticotropic hormone (ACTH) and cortisol response to a psychosocial laboratory stressor in adulthood. The data are from an epidemiological cohort study of the long-term outcome of early risk factors assessed at birth. At age 3 months, mothers and infants were videotaped during a 10-min standardized nursing and playing situation and evaluated by trained raters for maternal stimulation and infant and maternal responsiveness. At age 19 years, 270 participants (146 females, 124 males) completed the Trier Social Stress Test. The results indicated that less maternal stimulation during early interaction at age 3 months predicted diminished plasma ACTH and cortisol increase in response to acute psychosocial stress in male, but not female offspring. In contrast, maternal responsiveness was found to be unrelated to hypothalamic-pituitary-adrenal (HPA) reactivity. In accordance with the findings from animal research, the present study provides prospective evidence in humans of a long-term association between early maternal interaction behavior and the offspring's hormonal stress response in young adulthood, suggesting that poor maternal stimulation in early infancy may result in reduced HPA axis reactivity to an acute psychosocial stressor in males.
Evidence from animal research has revealed that less maternal care results in disturbed emotionality in the offspring. In the present study, the long-term impact of maternal responsiveness and stimulation during early mother child interaction on depressive psychopathology was examined until adulthood. Data are from an epidemiological cohort study of the long-term outcome of early risk factors assessed at birth. At age 3 months, mothers and infants were videotaped during a nursing and playing situation. Maternal responsiveness and stimulation as well as infant responsiveness were evaluated by trained raters. At age 19 years, 314 participants (145 males, 169 females) were characterized on measures of depression through interview and questionnaire. In addition, measures of depression and anxiety were available from assessments in childhood. Results indicated that less maternal stimulation during early interaction was associated with a higher risk of depression in the offspring until the age of 19 years. In addition, children of less stimulating mothers showed more depressive symptoms at age 19 years and displayed more anxiety and depressive symptoms between the ages of 4.5 and 15 years. In contrast, maternal responsiveness was unrelated to children's outcome. In accordance with findings from animal research, the present study provides first longitudinal evidence in humans of a continuous and long-term influence of early maternal interaction behavior on the offspring's psychological adjustment until adulthood. The results suggest that the amount of maternally initiated contact behavior in a very early developmental stage may be crucial for children's mental health, regardless of child and maternal responsiveness.
Recent evidence suggests that heterogeneity in the age at onset could explain the inconsistent findings of association studies relating the dopamine transporter (DAT1) gene with alcohol and nicotine consumption. The aim of this study was to examine interactions between two DAT1 polymorphisms and different initiation ages with regard to alcohol and tobacco consumption levels and dependence. Two hundred and ninety-one young adults (135 males, 156 females) participating in the Mannheim Study of Children at Risk were genotyped for the 40-bp variable number of tandem repeats (VNTR) and rs27072 polymorphisms of DAT1. Age at initiation was assessed at age 15 and 19 years. Information about current alcohol and tobacco consumption was obtained at age 19 years using self-report measures and structured interviews. Results suggest that age at onset of intensive consumption moderated the association of the DAT1 gene with early adult substance use and dependence, revealing a DAT1 effect only among individuals homozygous for the 10r allele of the 40-bp VNTR who had started daily smoking or being intoxicated early in life. Equally, carriers of the T allele of the rs27072 polymorphism reporting an early age at first intoxication showed higher current alcohol consumption at age 19 years. In contrast, no interaction between rs27072 and the age at first cigarette with regard to later smoking was observed. These findings provide evidence that the DAT1 gene interacts with an early heavy or regular drug exposure of the maturing adolescent brain to predict substance (ab)use in young adulthood. Further studies are required to confirm these findings.
Recent longitudinal studies have indicated that affective and behavioral dysregulation in childhood is associated with an increased risk for various negative outcomes in later life. However, few studies to date have examined early mechanisms preceding dysregulation during early childhood. Aim of this study was to elucidate early mechanisms relating to dysregulation in later life using data from an epidemiological cohort study on the long-term outcome of early risk factors from birth to adulthood. At age 3 months, mothers and infants were videotaped during a nursing and playing situation. Maternal responsiveness was evaluated by trained raters. Infant regulatory problems were assessed on the basis of a parent interview and direct observation by trained raters. At age 8 and 11 years, 290 children (139 males) were rated on the Child Behavior Checklist (CBCL). Additionally, participants were genotyped for the dopamine D4 receptor (DRD4) exon 3 VNTR polymorphism. A significant three-way interaction between maternal responsiveness, DRD4 genotype and infant regulatory problems was detected predicting the CBCL-dysregulation profile (CBCL-DP). Carriers of the DRD4 7r allele with regulatory problems at age 3 months showed significantly more behavior problems associated with the CBCL-DP during childhood when exposed to less maternal responsiveness. In contrast, no effect of maternal responsiveness was observed in DRD4 7r carriers without infant regulatory problems and in non-carriers of the DRD4 7r allele. This prospective longitudinal study extends earlier findings regarding the association of the CBCL-DP with early parenting and later psychopathology, introducing both DRD4 genotype and infant regulatory problems as important moderators. (C) 2015 Elsevier Ltd. All rights reserved.
The psycho-social development of both preterm and term children (n=347) whose mothers reported tocolytic treatment was assessed at the ages of 2, 4.5, 8 years. Term children exposed to tocolysis showed a higher rate of psychiatric disorders as well as poorer cognitive and motor performance than controls. In the preterm children no adverse impact of tocolysis could be found. The results are discussed concerning possible ways in which tocolytic treatment may influence child development. Restrictions because of the preliminary character of this study and the need of further prospective studies to clarify the developmental impact of tocolysis are also considered.
Objective: The delineation of developmental pathways to juvenile depressive symptoms is of major clinical interest because these are known to be predictive for adult mood disorders and for a range of other mental health problems. This study investigates the impact of child temperament and early maternal distress, both of which are known to influence children's emotional development, on preadolescent depression. Methods: In a prospective, longitudinal at-risk sample (163 boys, 178 girls), we assessed temperament at the age of 3 months and at 2 years, 4.5 years, and 8 years, respectively, and chronic maternal distress during infancy. Hierarchical linear regression analysis was used to investigate the prediction of depressive symptoms at the age of 11 years measured by the Child Depression Inventory. In addition, we controlled for psychosocial and obstetric perinatal risks and gender. Results: Psychosocial risks and self-control temperament made significant independent contributions to preadolescent depression, whereas fearful, difficult temperament and obstetric risks were unrelated to depressive outcome. Interestingly, a clear gender difference emerged with a significant prediction from maternal distress only in girls. Conclusions: Our data extend previous findings of a concurrent association between regulative temperament and juvenile depression to a predictive view. Furthermore, the results point toward gender-specific pathways to preadolescent depression and support earlier findings indicating that subclinical maternal distress may exert as detrimental effects on child development as clinical depression.
Objective: A difficult or undercontrolled temperament, as well as harsh parental discipline or a lack of warmth, has long been regarded as risk factors for the development of externalizing problems. In addition, it has been suggested that children with difficult temperament are especially susceptible to rearing influences. We investigated the impact of early temperament and parenting and their interactions on externalizing behavior at school age.
Methods: Participants were 148 boys and 160 girls from a prospective longitudinal study on a high-risk sample. At ages 3 months and 2 years, temperament was assessed by a highly structured parent interview and standardized behavioral observations. Maternal parenting was assessed by videotaped behavioral observation and a parent questionnaire. Externalizing problems at age 8 years were measured by the Child Behavior Checklist.
Results: Using hierarchical linear regression analyses, we found that externalizing problems were predicted by psychosocial adversity and poor self-control, whereas no main effect for restrictive parenting or maternal empathy was found. Fearful-inhibited boys were positively affected by empathic and sensitive parenting, whereas girls who were low in self-control and/or fearful developed less externalizing problems with restrictive parenting.
Conclusion: Our results partly support the differential susceptibility hypothesis. In addition, they point toward gender-specific pathways in the development of externalizing problems.