Estimating genetic and environmental influences on depressive symptoms in adolescence: differing effects on higher and lower levels of symptoms

Twenty-Five Years of National-Level Research on Adolescent and Young Adult Mental Health in the United States

The longitudinal, population-level, biosocial data in the National Longitudinal Study of Adolescent to Adult Health (Add Health) have elucidated the developmental course of mental health across early stages of the life course. This data set also has been invaluable for documenting and unpacking disparities in these developmental patterns by race, ethnicity, socioeconomic status, gender, immigration, and sexuality. Reflecting the larger focus of this special supplement on Add Health as a tool for connecting adolescence to adulthood, this article reviews Add Health research since 2000 based on a search of key mental health terms, primarily describing patterns of two key markers of psychopathology (depressive symptoms, suicidal ideation) that were consistently measured across waves. It situates these patterns from adolescence into adulthood within the developmental ecology organized by the proximate settings of everyday life, the larger social structures organized by a highly stratified society, and the relations of these ecological and structural forces to biological processes. Major foci are the dynamic nature of mental health across the life course and the ways that ecological and physiological influences on mental health differ by group identity and social position.

Social, behavioral, and genetic linkages from adolescence into adulthood

The influence of genetic factors on health and behavior is conditioned by social, cultural, institutional, and physical environments in which individuals live, work, and play. We encourage studies supporting multilevel integrative approaches to understanding these contributions to health, and describe the Add Health study as an exemplar. Add Health is a large sample of US adolescents in grades 7 to 12 in 1994-1995 followed into adulthood with 4 in-home interviews and biomarker collections, including DNA. In addition to sampling multiple environments and measuring diverse social and health behavior, Add Health features a fully articulated behavioral genetic sample (3000 pairs) and ongoing genotyping of 12,000 archived samples. We illustrate approaches to understanding health through investigation of the interplay among biological, psychosocial, and physical, contextual, or cultural experiences.

Interactions Between MAOA Genotype and Receipt of Public Assistance: Predicting Change in Depressive Symptoms and Body Mass Index

Response to stress is determined in part by genetically-influenced regulation of the monoamine system. We examined the interaction of a stressor (receipt of public assistance) and a gene regulating the monoamine system (MAOA) in the prediction of change in adolescent depressive symptoms and body mass index (BMI). Participants were drawn from the National Longitudinal Study on Adolescent Health (AddHealth) genetically-informative subsample. We focused on males due to the fact that males only have one MAOA allele. Growth curve analyses were conducted to assess the association between public assistance, MAOA allele, and their interaction and the intercept and slope of depressive symptoms and BMI. The results indicated that among males, MAOA allele type interacted with receipt of public assistance in the prediction of rate of change in both depressive symptoms and BMI from early adolescence through early adulthood. Males with the short MAOA allele whose families received public assistance tended to experience increased growth in depressive symptoms and BMI. Implications of the findings for understanding the relations among stress, physiology, and development are discussed.

Genetic and environmental influences upon the CBCL/6-18 DSM-oriented scales: similarities and differences across three different computational approaches and two age ranges

Inasmuch as the newly established DSM-oriented CBCL/6-18 scales are to be increasingly employed to assess clinical/high-risk populations, it becomes important to explore their aetiology both within the normal- and the extreme range of variation in general population samples and to compare the results obtained in different age groups. We investigated by the Quantitative Maximum Likelihood, the De Fries-Fulker, and the Ordinal Maximum Likelihood methods the genetic and environmental influences upon the five DSM-oriented CBCL/6-18 scales in 796 twins aged 8-17 years belonging to the general population-based Italian Twin Registry. When children were analysed together regardless of age, most best-fitting solutions yielded genetic and non-shared environmental factors as the sole influences for DSM-oriented CBCL/6-18 behaviours, both for the normal and the extreme variations. When analyses were conducted separately for two age groups, shared environmental influences emerged consistently for Affective and Anxiety Problems in children aged 8-11. Oppositional-Defiant, Attention Deficit/Hyperactivity, and Conduct Problems appeared-with few exceptions-influenced only by genetic and non-shared environmental factors in both age groups, according to all three computational approaches. The De Fries-Fulker method appeared to be more sensitive in detecting shared environmental effects. Analysing the same set of data with different analytic approaches leads to better-balanced views on the aetiology of psychopathological behaviours in the developmental years.

Longitudinal associations between depressive symptoms and alcohol problems: The influence of comorbid delinquent behavior

OBJECTIVE

Although numerous studies have demonstrated a positive association between depressive symptoms and alcohol problems and related disorders, it remains unclear whether this link can be explained by the joint co-occurrence of these disorders with delinquent behavior. This study examined the longitudinal associations between depressive symptoms and alcohol problems from early adolescence through early adulthood, while accounting for delinquent behavior and the potential interaction effects between delinquent behavior and each of these problems.

METHOD

The National Longitudinal Study of Adolescent Health sample of 20,728 adolescents, followed for 6 years, was used. Males and females were examined separately. Multilevel modeling was used to predict both initial levels and rate of change in alcohol problems based on levels of depressive symptoms and delinquent behavior (and their interaction), and initial level and rate of change in depressive symptoms based on alcohol problems and delinquent behavior (and their interaction).

RESULTS

Once delinquent behavior was included in the model, the reciprocal positive associations between alcohol problems and depressive symptoms tended to remain significant. Some interactive effects between delinquent behavior and these problems were found, mainly in females.

CONCLUSIONS

The reciprocal positive associations between alcohol problems and depressive symptoms over time are not fully due to their joint co-occurrence with delinquent behavior, though delinquent behavior does moderate these links in some cases.

Depression and anxiety symptoms: onset, developmental course and risk factors during early childhood

BACKGROUND

Depressive and anxiety disorders are among the top ten leading causes of disabilities. We know little, however, about the onset, developmental course and early risk factors for depressive and anxiety symptoms (DAS).

OBJECTIVE

Model the developmental trajectories of DAS during early childhood and to identify risk factors for atypically high DAS.

METHOD

Group-based developmental trajectories of DAS conditional on risk factors were estimated from annual maternal ratings (1(1/2) to 5 years) in a large population sample (n = 1759).

RESULTS

DAS increased substantially in two of the three distinct trajectory groups identified: High-Rising (14.7%); Moderate-Rising (55.4%); and Low (29.9%). Two factors distinguished the High-Rising group from the other two: Difficult temperament at 5 months (High-Rising vs Moderate-Rising: OR = 1.32; 95% CI = 1.13-1.55; High-Rising vs Low: OR = 1.31, CI = 1.12-1.54) and maternal lifetime major depression (High-Rising vs Moderate-Rising: OR = 1.10; CI = 1.01-1.20; High-Rising vs Low: OR = 1.19; CI = 1.08-1.31). Two factors distinguished the High-Rising group from the Low group: High family dysfunction (OR = 1.24; CI = 1.03-1.5) and Low parental self-efficacy (OR = .71; CI = .54-.94).

CONCLUSIONS

DAS tend to increase in frequency over the first 5 years of life. Atypically high level can be predicted from mother and child characteristics present before 6 months of age. Preventive interventions should be experimented with at risk infants and parents.

Longitudinal associations between alcohol problems and depressive symptoms: early adolescence through early adulthood

BACKGROUND

Alcohol use-related problems and depressive symptoms are clearly associated with each other, but results regarding the nature of this association have been inconsistent. In addition, the possible moderating effects of age and gender have not been comprehensively examined. The goals of this study were to clarify: (i) how depressive symptoms affect the levels and trajectory of alcohol use-related problems, (ii) how alcohol use-related problems affect the levels and trajectory of depressive symptoms, and (iii) whether there are differences in these associations at different points in development or between males and females.

METHODS

Participants for this study were drawn from the National Longitudinal Study of Adolescent Health (AddHealth) data set, a community-based sample of 20,728 adolescents followed from adolescence through early adulthood. Multilevel models were used to assess how each problem affected the level and rate of change in the other problem over time; gender was considered as a possible moderator of these associations.

RESULTS

The results indicated that alcohol use-related problems and depressive symptoms had reciprocal, positive associations with each other during the period from early adolescence through early adulthood; however, these effects differed somewhat by gender and age. High levels of depressive symptoms were associated with higher initial levels of alcohol problems (particularly among females), as well as faster increases in alcohol problems over time among males. High levels of alcohol problems were associated with higher initial levels of depressive symptoms (particularly among females), as well as less curvature in the slope of depressive symptoms so that although there was a large difference between people with high and low depressive symptoms in early adolescence, by early adulthood the difference was smaller (particularly among females).

CONCLUSIONS

These results highlight the importance of examining gender and age in studies on the associations between affective disorders and substance use disorders.

Depression and internally directed aggression: genetic and environmental contributions

This study uses behavior genetic (BG) methodology to investigate Freud's theory of depression as aggression directed toward the self (1930) and the extent to which genetically and environmentally influenced aggressive tendencies contribute to depressive symptoms. Data from the Twin and Offspring Study in Sweden (TOSS) is used to demonstrate how, in estimating shared and unique environmental influences, BG methods can inform psychoanalytic theory and practice, particularly because of their shared emphasis on the importance of individual experience in development. The TOSS sample consists of 909 pairs of adult twins, their partners, and one adolescent child per couple. The Center for Epidemiologic Studies Depression Scale (Radloff 1977) was used to measure depressive symptoms and the Karolinska Scales of Personality (Schalling and Edman 1993) to measure internally directed aggression. Genetic analyses indicated that for both men and women, their unique experiences as well as genetic factors contributed equally to the association between internally directed aggression and depressive symptoms. These findings support Freud's theory that constitutionally based differences in aggression, along with individual experiences, contribute to a person's depressive symptoms. Establishing that an individual's unique, not shared, experiences and perceptions contribute to depressive symptoms and internally directed aggression reinforces the use of patient-specific treatment approaches implemented in psychoanalytic psychotherapy or psychoanalysis.