Effect of the serotonin transporter gene and of environment on the continuity of anxiety and depression traits throughout adolescence

Twenty years of emotional-behavioral problems of community adolescents living in Italy measured through the Achenbach system of empirically based assessment (ASEBA): a systematic review and meta-analysis

Background

This is a systematic review and meta-analysis of emotional and behavioral problems among Italian community adolescents in the last 20 years, as assessed through the ASEBA questionnaires CBCL 6-18, YSR 11-18 and TRF 6-18. Research questions address: (1) pooled means of problems' scores in questionnaires scales; (2-3) variations in scores according to sociodemographic and time-related factors, and studies' quality; (4) trends in research with ASEBA instruments along with other outcomes, e.g., psychopathological symptoms.

Methods

A systematic literature review of Scopus, EBSCO, PubMed, Web of Science, and ProQuest databases using the PRISMA 2020 guidelines was conducted on November, 2021, and of grey literature on December, 2021. The quality of studies was assessed through the Newcastle-Ottawa Scale.

Results

Forty-four studies were eligible for the systematic review, of which 34 were included for meta-analysis. Results showed that: (1) emotional-behavioral problems were higher when assessed by the CBCL and lower when assessed by the YSR compared to normative data; (2) there were no gender and age differences, except for higher scores of Anxious/Depression symptoms, in girls. (3) internalizing and attention problems increased over the last two decades. (4) major trends of Italian research investigate adolescents' emotional behavioral problems concerning attachment, comorbid symptoms, especially internet addictions, and eating disorders.

Discussion

Despite some limitations (e.g., low-medium quality of most studies, no data on the TRF, under-representation of some geographical areas, some search-related choices), these data provides Italian practitioners and international researchers of some parameter to evaluate Italian adolescents emotional-behavioral problems. Registered on PROSPERO N. CRD42022299999.

Gene-Environment Interactions in Psychiatry: Recent Evidence and Clinical Implications

PURPOSE OF REVIEW

We identify the recent evidence for gene-by-environment interaction studies in relation to psychiatric disorders. We focus on the key genotypic data as well as environmental exposures and how they interact to predict psychiatric disorders and psychiatric symptomatology. We direct our focus on the psychiatric outcomes that were focused on by the Psychiatric Genetics Consortium.

RECENT FINDINGS

Many of the studies focus on candidate gene approaches, with most of the studies drawing upon previous literature to decide the genes of interest. Other studies used a genome-wide approach. While some studies demonstrated positive replication of previous findings, replication is still an issue within gene-by-environment interaction studies. Gene-by-environment interaction research in psychiatry globally suggests some susceptibility to environmental exposures based on genotype; however, greater clarity is needed around the idea that genetic risk may not be disorder specific.

Strong Homotypic Continuity in Common Psychopathology-, Internalizing-, and Externalizing-Specific Factors Over Time in Adolescents

Dimensional models of psychopathology have recently gained prominence that posit a general psychopathology factor (i.e., p factor), in addition to specific internalizing and externalizing factors. However, the stability of these factors, and the specificity with which they are related to one another over time (e.g., homotypic or heterotypic continuity), have not been investigated. The current study addressed these questions. We estimated bifactor models, with p, internalizing-specific and externalizing-specific factors, with youth and caretaker report of symptoms at two time points (18 months apart), in a large community sample of adolescents. Results showed strong stability over time with highly specific links (i.e., p factor at Time 1 to Time 2; internalizing-specific at Time 1 to Time 2, externalizing-specific at Time 1 to Time 2), suggesting strong homotypic continuity between higher-order latent psychopathology factors.

Genetic Polymorphism in the Promoter Region of Serotonin Transporter: Implications for Ethanol Abuse in Children and Adolescents

OBJECTIVES

To provide a review of published literature regarding genetic polymorphism of serotonin transporter gene, named as 5-HTTLPR, and its potential role as a susceptibility marker for ethanol abuse in childhood and adolescence.

METHODS

A literature review of several databases was conducted with the following keywords: 5-HTTLPR, children or adolescents or teenagers, susceptibility, alcohol or ethanol, abuse or misuse.

RESULTS

Alcohol interacts with serotonergic synaptic transmission in several ways, and the reduced availability of serotonin transporters might foster brain dysfunction, driving to alcohol abuse. The initial use of ethanol in children and adolescents is determined primarily by environmental influences, whereas the establishment of drinking patterns is strongly controlled by genetic factors. Functional polymorphic variants in the promoter region of the 5-HTTLPR gene have age-dependent effects in alcohol abuse. This polymorphism, mapped to the 5' region of the SLC6A4, is a variable number of tandem repeats (VNTR) and involves a direct repeat of 20-23 base pairs GC-rich sequences, comprising a short (S) allele, consisting of 14 repeats, and a long (L) allele, with 16 repeats. Additional variants have been described, although their influences on childhood and adolescence ethanol use are not clear.

CONCLUSION

The influence of the 5-HTTLPR allelic variants in children and adolescent misuse of alcohol might be considered for clinical management, preventing long-term behavior problem. Identifying genetic markers associated to the potential alcohol misuse or abuse could be useful in guiding management and formulating effective coping strategies.

Effect of family structure and TPH2 G-703T on the stability of dysregulation profile throughout adolescence

BACKGROUND

Two different polymorphisms (TPH2 G-703T and 5-HTTLPR) involved in the serotonergic pathway have been reported to play a role, both alone and in interaction with the environment, in early and adult emotion regulation. As most of these studies are cross-sectional, we know little about the impact of these polymorphisms over time, particularly during adolescence.

METHODS

Because we were interested in the effects of these polymorphisms and environment (i.e., family structure) at different time-points on the emotional dysregulation profile, we performed a path analysis model in a general adolescent population sample of a five-year follow-up study.

RESULTS

We found a high stability of Dysregulation Profile problems independently from the examined allelic variants. We also found that early family structure directly influences the levels of dysregulation problems in early adolescence, both alone and in interaction with TPH2, suggesting the presence of a gene-environment interaction effect. Furthermore, we found that in adolescents homozygous for the TPH2 G allele, the effect of the early family structure remains active during late adolescence, albeit mediated by earlier emotional problems.

LIMITATIONS

The high attrition rate, the use of only one source on behavioral problems of adolescents, and the focus on a single polymorphism in the investigated genes could limit the generalizability of the present results.

CONCLUSIONS

These results suggest that early family structure could play a significant role in the development and maintenance of emotional and behavioral problems not only in early adolescence but also in late-adolescence, although this effect was mediated and moderated by behavioral and genetic variables.

Monoamine oxidase A polymorphism moderates stability of attention problems and susceptibility to life stress during adolescence

Attention problems affect a substantial number of children and adolescents and are predictive of academic underachievement and lower global adaptive functioning. Considerable variability has been observed with regard to the individual development of attention problems over time. In particular, the period of adolescence is characterized by substantial maturation of executive functioning including attentional processing, with the influence of genetic and environmental factors on individual trajectories not yet well understood. In the present investigation, we evaluated whether the monoamine oxidase A functional promoter polymorphism, MAOA-LPR, plays a role in determining continuity of parent-rated attention problems during adolescence. At the same time, a potential effect of severe life events (SLEs) was taken into account. A multi-group path analysis was used in a sample of 234 adolescents (149 males, 85 females) who took part in an epidemiological cohort study at the ages of 11 and 15 years. Attention problems during early adolescence were found to be a strong predictor of attention problems in middle adolescence. However, in carriers of the MAOA-LPR low-activity variant (MAOA-L), stability was found to be significantly higher than in carriers of the high-activity variant (MAOA-H). Additionally, only in MAOA-L carriers did SLEs during adolescence significantly impact on attention problems at the age of 15 years, implying a possible gene × environment interaction. To conclude, we found evidence that attention problems during adolescence in carriers of the MAOA-L allele are particularly stable and malleable to life stressors. The present results underline the usefulness of applying a more dynamic GxE perspective.

G × E interaction and neurodevelopment II. Focus on adversities in paediatric depression: the moderating role of serotonin transporter

In a short series of articles, we will review the evidence for genotype by environment interaction (G × E) in developmental psychopathology. We will focus specifically on the characteristics of types of exposure assessed with respect to both their methods and findings. This article aims to review the studies exploring the moderating role of serotonin transporter on the effect of environmental adversities over time, particularly during childhood and adolescence, which is when level of internalizing symptoms and prevalence of mood disorders change substantially. Environmental adversities will not include abuse and maltreatment that have been reviewed before (see Bellani et al. 2012) and child's broader social ecology that will be reviewed in the next section.