Major psychiatric disorders including alcohol use disorder are considered multigenic and the smallness of effects of individual genes may be attributed to either complex biological mechanisms or geneenvironment interactions. The latter explanation is highlighted by the relatively fast changes in secular trends and in cohort effects on alcohol use disorder. Interactions of candidate gene variants with birth cohort have been found in the Estonian Children Personality Behaviour and Health Study, a longitudinal investigation from 1998 with a sample highly representative of birth cohorts within a region. Such interactions regarding initiation of alcohol use or alcohol use disorder have been revealed for e.g., 5-HTTLPR, VMAT1, OXR and NRG1, and suggest that rapid alterations in the socioeconomic environment promote changes in the genetic vulnerability to environmental risks factors such as alcohol.
Abstract Objective: Reward sensitivity is an increasingly used construct in psychiatry, yet its possible inner structure and relationship with other affective variables are not well known. Methods: A reward sensitivity measurement scale was constructed on the basis of large item pool collected from birth cohort representative samples (the Estonian Children Personality Behaviour and Health Study; original n = 1238). Affective Neuroscience Personality Scale (ANPS) and the Adult Attention deficit hyperactivity disorder (ADHD) Self-Report Scale (ASRS) were administered in young adulthood. A variant (rs4570625) of the gene encoding tryptophan hydroxylase 2 ( TPH2 ) that is responsible for the synthesis of central serotonin was genotyped. Results: Reward sensitivity consisted of two orthogonal components, operationally defined as Openness to Rewards and Insatiability by Reward, that respectively characterise the striving towards multiple rewards and the strong pursuit and fixation to a particular reward. While SEEKING and PLAY (and to lower extent CARE) of the ANPS co-varied with Openness to Rewards, FEAR, SADNESS, and ANGER were related to Insatiability by Reward. The total score of ASRS was moderately correlated with Insatiability by Reward, while the association with Openness to Rewards was negligible. However, ASRS Inattention had some negative relationship with the Social Experience facet of Openness to Rewards. The T/T homozygotes for the TPH2 promoter polymorphism had lower Insatiability by Reward but not Openness to Rewards. Conclusions: Behaviours sensitive to rewards are separable to the components of variability and fixation, and these components are differentially related to affective aspects of personality, attention, and hyperactivity as well as to TPH2 genotype.
Background: The neuregulin 1 gene is a susceptibility gene for substance dependence. A functional polymorphism (SNP8NRG243177/rs6994992; C/T) in the promoter region of the brain-specific type IV neuregulin-1 gene ( NRG1) has been associated with psychiatric disorders (e.g. schizophrenia and bipolar disorder) that often present higher odds of smoking, alcohol and illicit drug use. This study assessed the association of the NRG1 genotype with drug use and possible interaction with stressful life events (SLEs). Methods: The database of the Estonian Children Personality Behaviour and Health Study (beginning in 1998) was used. Cohorts of children initially 9 years old ( n=583; followed up at 15 and 18 years) and 15 years old ( n=593; followed up at 18 and 25 years) provided self-reports on alcohol, tobacco and illicit substance use and SLEs. Psychiatric assessment based on DSM-IV was carried out on the older birth cohort at age 25 to assess the lifetime presence of substance use disorders. NRG1 rs6994992 was genotyped in all participants by TaqMan® Pre-Designed SNP Genotyping Assay on the Applied Biosystems ViiA™ 7 Real-Time PCR System. The minor (T) allele frequency was 0.37. Results: NRG1 rs6994992 C/C homozygotes, especially those who had experienced more SLEs, were more likely to develop alcohol use disorders by young adulthood, were generally more active consumers of tobacco products, and had more likely used illicit drugs. In T allele carriers, SLEs had a negligible effect on substance use. Conclusions: In humans, NRG1 genotype is associated with substance use, and this relationship is moderated by adverse life events, with a gain-of-function allele being protective.
Kõigil õpetajatel ja õppejõududel on vajalik arendada enda õpetamisoskusi. On vaja märgata õppijate õpistrateegiaid, aidata kujundada arusaamu teaduse olemusest praeguses infoküllases ühiskonnas, kujundada tänapäevastel töökohtadel vajalikke koostööoskusi ja teisi üldpädevusi ning mõista, et tähelepanu vajavad ka täiskasvanud õppijad. EHA vabanumber pakub lugejale teadusuuringute ja raamatututvustusega võimalust mõelda kaasa, kuidas märgata õppijate õppimist ning arendada enda õpetamisoskusi teadlikult, andmaks kvaliteetset haridust kõigil haridusastmetel.
Impulsivity represents a complex human behavior characterized by little or no forethought, reflection, or consideration of the consequences. The definitions of impulsivity include a number of subtraits, such as risk taking, lack of planning, making up one’s mind quickly, acting on the spur of the moment (motor activation), not focusing on the task at hand (attention), and not planning and thinking carefully (lack of planning). Evidence from different genetic and neuroimaging studies suggest that biopsychosocial factors and their interaction affect the development of impulsivity ; however the underlying biological substrates are not yet fully defined. Biological factors are greatly influenced by a variety of genetic and non- genetic factors. Although impulsivity represents one of the diagnostic criteria for several psychiatric disorders, its complex role is still not fully clarified. There is a large body of behavioral, personality, psychological, biological and neurological research on impulsivity, with a great interest in identifying biomarkers associated with this trait. Impulsivity is moderated through a network of different cortical regions such as medial and dorsolateral prefrontal cortices, and the subcortical ventral striatum. These results suggest that structures mediating reward related decision-making are associated with impulsivity. Biomarkers are objective, quantifiable characteristics of biological processes. As impulsive behavior has been associated, primarily, with functional changes in serotonergic, dopaminergic, and noradrenergic systems, our aim was to investigate the biological and genetic markers of impulsivity, especially those related to dopaminergic and serotonergic systems in children and adolescents. In this chapter we have presented the results regarding association of impulsivity with peripheral biochemical markers such as platelet serotonin (5-HT) concentration and platelet monoamine oxidase (MAO-B) activity. Moreover, we have investigated the potential genetic markers of impulsivity, such as different variants of the genes encoding catechol-o-methyl transferase (COMT), dopamine-beta-hydroxylase (DBH), monoamine oxidase type B (MAO-B), dopamine receptor type 4 (DRD4) and serotonin transporter (5-HTT). Our findings might contribute to a more complete understanding of the etiology of impulsive behavior and lead to improvements in the treatment of a variety of psychiatric disorders.
This study examined the relationship between alcohol/illicit drug use, the Five-Factor Model (FFM) personality traits, aggressiveness (Agg), and hyperactivity (Hyp), and platelet monoamine oxidase (MAO) activity in a population-derived representative sample of preadolescents and adolescents (n=1172). Alcohol and illicit drug use was self-reported. The FFM personality inventories were filled in by mothers of the participants, and Agg and Hyp were rated by their class teachers. Higher scores in extraversion (E), Agg, and Hyp and lower scores in conscientiousness (C) together with older age were significant predictors of more frequent alcohol use in adolescents. No significant association was found between alcohol illicit drug use, and platelet MAO activity. D 2002 Elsevier Science Ltd. All rights reserved.
