Incorporating the family as a critical context in genetic studies of children: implications for understanding pathways to risky behavior and substance use

Multi-type childhood maltreatment exposure and substance use development from adolescence to early adulthood: A GxE study

BACKGROUND

Childhood maltreatment types can co-occur and are associated with increased substance use during adolescence and early adulthood. There is also a strong genetic basis for substance use which interacts with environmental factors (e.g., childhood maltreatment) to influence substance use phenotype.

OBJECTIVE

This research aimed to identify childhood maltreatment sub-groups based on type and chronicity, and their association with substance use change from adolescence to early adulthood, while accounting for the influence of substance use polygenic risk (i.e., genetic risk based on the combined effects of multiple genes).

PARTICIPANTS

We used a sample of unrelated European-origin Americans with genetic and childhood maltreatment data (n = 2,664) from the National Longitudinal Study of Adolescent to Adult Health.

METHODS

Latent profile analysis was used for sub-group identification and direct and interaction effects were tested for longitudinal trajectories of substance use utilizing generalized estimating equations.

RESULTS

Three sub-groups with co-occurring childhood maltreatment exposures were identified: a high sexual abuse sub-group, a high physical abuse sub-group, and a normative sub-group (with low maltreatment exposure). At high polygenic risk, the high physical abuse sub-group had faster increases in substance use over time. In comparison, the high sexual abuse sub-group had faster progression in substance use only at low and medium polygenic risk.

CONCLUSIONS

Findings provide initial evidence for biological and environmental differences among maltreatment sub-groups on trajectories of substance use.

Estimating the familial risk of psychiatric illnesses: A review of family history scores

A history of psychiatric illnesses in family members of those diagnosed to have an illness has been of significant interest both in research and in clinical practice. Almost all of the major psychiatric illnesses have a familial component to them, perhaps influenced by genetics and a shared environment or their combination. Systematic attempts have been made to quantify these familial risks, as obtained from family history (FH) of psychiatric illnesses. The methods range from a simple dichotomous or count scores to those quantifying as weighted risks such as the Family history density (FHD) measures. This article reviews the available literature on such FH methods and discusses their advantages and limitations. Validation studies have shown that FHD measures may be preferred over dichotomous measures as indicators of familial risk. However, the FHD method has certain limitations, like mostly relying on categorical diagnosis and ignoring other familial risk factors. By critically analysing various existing density measures based on 'ideal characteristics', we suggest a modified version of FHD that would benefit psychiatric research.

Four Actionable Bottlenecks and Potential Solutions to Translating Psychiatric Genetics Research: An Expert Review

BACKGROUND

Psychiatric genetics has had limited success in translational efforts. A thorough understanding of the present state of translation in this field will be useful in the facilitation and assessment of future translational progress.

PURPOSE

A narrative literature review was conducted. Combinations of 3 groups of terms were searched in EBSCOhost, Google Scholar, and PubMed. The review occurred in multiple steps, including abstract collection, inclusion/exclusion criteria review, coding, and analysis of included papers.

RESULTS

One hundred and fourteen articles were analyzed for the narrative review. Across those, 4 bottlenecks were noted that, if addressed, may provide insights and help improve and increase translation in the field of psychiatric genetics. These 4 bottlenecks are emphasizing linear translational frameworks, relying on molecular genomic findings, prioritizing certain psychiatric disorders, and publishing more reviews than experiments.

CONCLUSIONS

These entwined bottlenecks are examined with one another. Awareness of these bottlenecks can inform stakeholders who work to translate and/or utilize psychiatric genetic information. Potential solutions include utilizing nonlinear translational frameworks as well as a wider array of psychiatric genetic information (e.g., family history and gene-environment interplay) in this area of research, expanding which psychiatric disorders are considered for translation, and when possible, conducting original research. Researchers are urged to consider how their research is translational in the context of the frameworks, genetic information, and psychiatric disorders discussed in this review. At a broader level, these efforts should be supported with translational efforts in funding and policy shifts.

Maternal risk taking on the balloon analogue risk task as a prospective predictor of youth alcohol use escalation

The transition from late childhood through middle adolescence represents a critical developmental period during which there is a rapid increase in the initiation and escalation of alcohol use. Alcohol use is part of a constellation of risk taking behaviors that increase during this developmental transition, which can be explained by environmental and genetic factors. Social learning theory (SLT) implicates observations of parental drinking in the development of alcohol use in youth. Parental risk taking more broadly has not previously been examined as a factor predictive of alcohol use escalation in youth across adolescence. The current study examined the relative contributions of maternal risk taking on the Balloon Analogue Risk Task (BART) and maternal alcohol use in the prediction of alcohol escalation among youth over three years. Participants were a sample of 245 youth (55.0% male, 49.6% Caucasian) who participated annually between grades 8 and 10, drawn from a larger study of adolescent risk taking. Within our sample, maternal risk taking, as measured by the BART, predicted increases in alcohol use. Interestingly, maternal alcohol use and other youth factors were not predictive of escalations in youth alcohol use. Our findings suggest the importance of considering maternal riskiness more broadly, rather than solely focusing on maternal alcohol use when attempting to understand youth alcohol use across adolescence. These findings emphasize the relevance of maternal risk taking as measured by a behavioral task and suggest a general level of riskiness displayed by mothers might encourage youth to behave in a riskier manner themselves.

Overview of Behavioral Genetics Research for Family Researchers

This article provides an overview of the methods, assumptions, and key findings of behavioral genetics methodology for family researchers with a limited background. We discuss how family researchers can utilize and contribute to the behavioral genetics field, particularly in terms of conducting research that seeks to explain shared environmental effects. This can be done, in part, by theoretically controlling for genetic confounds in research that seeks to determine cause-and-effect relationships among family variables and individual outcomes. Gene-environment correlation and interaction are especially promising areas for the family researcher to address. Given the methodological advancements in the field, we also briefly comment on new methods in molecular genetics for studying psychological mental health disorders.

Shared environmental contributions to substance use

The current study examined the association between substance use in the household during childhood, parental attitudes towards substance use and lifetime substance use in males. Subjects included 1081 monozygotic and 707 dizygotic twins from the Virginia Adult Twin Study of Psychiatric and Substance Use Disorders. Retrospective reports of substance use and features of the family environment (adult household substance use and parental attitudes towards substance use) were obtained using a life history interview. A trivariate Cholesky decomposition was conducted using the program Mx to decompose common shared environmental variance. Findings suggest that family environmental factors accounted for a large proportion of the shared environmental effects for illicit drug use. Results illustrate an important way of extending behavior genetic research to reveal specific etiological environmental mechanisms.

Commentary: trailblazing a research agenda at the interface of pediatrics and genomic discovery--a commentary on the psychological aspects of genomics and child health

Unprecedented advances in human genome science are underway with potential to benefit public health. For example, it is estimated that within a decade, geneticists and epidemiologists will complete a catalog of the majority of genes associated with common chronic diseases. Such rapid advances create possibilities, if not the mandate, for translational research in how best to apply these and other anticipated discoveries for both individual and population health benefit. Driving these discoveries are rapid advances in infrastructure (e.g., the International HapMap Project to catalog human genetic variation; http://www.hapmap.org), analytical methods, and technology. This expansion in capabilities quickly has taken us from a genetics paradigm-where the influence of individual genes on health outcomes is paramount, to a genomics paradigm-where the complex influence of individual genes is considered in concert with each other and with environmental exposures on health outcomes. We discuss these and similar groundbreaking discoveries with an eye toward understanding their importance to child health and human development, and the role of behavioral science research conducted at the interface of pediatrics and genomic discovery.