Etiological heterogeneity of symptom dimensions of adolescent depression

Childhood maltreatment, multilocus HPA-axis genetic variation and adolescent comorbidity profiles of depressive and anxiety symptoms

BACKGROUND

Despite a growing body of evidence showing both genetic and environmental influences on adolescent depression and anxiety, the involved comorbid mechanisms regarding gene-by-environment (G × E) interaction remain unclear.

OBJECTIVE

The current study was the first to investigate the extent to which multilocus hypothalamic-pituitary-adrenal (HPA)-axis genetic variants moderated the association between childhood maltreatment and adolescent comorbid depression and anxiety.

METHODS

The participants were 827 Chinese Han adolescents (Mage = 16.45 ± 1.37 years; 50.2 % girls). A theory-driven multilocus genetic profile score (MGPS) was computed by calculating alleles of core HPA-axis genes (CRHR1, NR3C1, NR3C2, and FKBP5) associated with heightened stress reactivity. Childhood maltreatment was retrospectively collected using Childhood Trauma Questionnaire. Comorbidity profiles of self-reported adolescent depressive and anxiety symptoms were constructed via person-centered latent profile analysis.

RESULTS

Three heterogeneous comorbidity profiles of depressive and anxiety symptoms were identified: comorbid severe symptoms (9.7 %), comorbid moderate symptoms (46.4 %) and comorbid mild symptoms (43.9 %). The HPA-axis related MGPS significantly interacted with childhood maltreatment, especially emotional maltreatment (emotional abuse: OR = 1.14, 95 % CI [1.03, 1.26], p < .01; emotional neglect: OR = 1.07, 95 % CI [1.01, 1.13], p < .05), to distinguish the comorbid severe symptoms profile from the comorbid mild symptoms profile (OR = 1.03, 95 % CI [1.01, 1.06], p < .05).

CONCLUSION

The HPA-axis related genes showed an additive polygenic sensitivity toward childhood maltreatment, which might be one of the polygenic G × E mechanisms underlying adolescent comorbid depression and anxiety.

Perceived causal symptom network of adolescent mental health issues

Adolescent mental health is difficult to capture in categories such as depression or specific anxiety disorders. An alternative is to approach psychiatric symptoms as causal networks, potentially revealing feedback loops that maintain a pathological state. One approach to creating such networks, implemented in the PECAN methodology, is to ask adolescents about their perceptions of the causes to their symptoms. For this purpose, a transdiagnostic item list was created, and adolescents who screened positive for depression (N = 55) completed twice in two weeks a survey quantifying perceptions of causality between their mental health problems. A network that was averaged across all participants was reliable and revealed three strong feedback loops: a first loop running through stress, insomnia, fatigue, procrastination, and back to stress; a second loop between stress and overthinking; and a third loop between stress and procrastination. Although all adolescents in the study screened positive for depression, symptoms of depression were not particularly central to the network. Instead, the most central symptoms were procrastination and overthinking. The average test-retest reliability for individual networks was low, limiting clinical application. In conclusion, PECAN was found to be reliable and useful when creating a group-level network of adolescent mental health problems. While informative at a group level, the method should be improved before it can be used to inform treatment at the individual level.

Repetitive Transcranial Magnetic Stimulation for Adolescent Major Depressive Disorder: A Focus on Neurodevelopment

Adolescent depression is a potentially lethal condition and a leading cause of disability for this age group. There is an urgent need for novel efficacious treatments since half of adolescents with depression fail to respond to current therapies and up to 70% of those who respond will relapse within 5 years. Repetitive transcranial magnetic stimulation (rTMS) has emerged as a promising treatment for major depressive disorder (MDD) in adults who do not respond to pharmacological or behavioral interventions. In contrast, rTMS has not demonstrated the same degree of efficacy in adolescent MDD. We argue that this is due, in part, to conceptual and methodological shortcomings in the existing literature. In our review, we first provide a neurodevelopmentally focused overview of adolescent depression. We then summarize the rTMS literature in adult and adolescent MDD focusing on both the putative mechanisms of action and neurodevelopmental factors that may influence efficacy in adolescents. We then identify limitations in the existing adolescent MDD rTMS literature and propose specific parameters and approaches that may be used to optimize efficacy in this uniquely vulnerable age group. Specifically, we suggest ways in which future studies reduce clinical and neural heterogeneity, optimize neuronavigation by drawing from functional brain imaging, apply current knowledge of rTMS parameters and neurodevelopment, and employ an experimental therapeutics platform to identify neural targets and biomarkers for response. We conclude that rTMS is worthy of further investigation. Furthermore, we suggest that following these recommendations in future studies will offer a more rigorous test of rTMS as an effective treatment for adolescent depression.

Research Review: Brain network connectivity and the heterogeneity of depression in adolescence - a precision mental health perspective

BACKGROUND

Adolescence is a period of high risk for the onset of depression, characterized by variability in symptoms, severity, and course. During adolescence, the neurocircuitry implicated in depression continues to mature, suggesting that it is an important period for intervention. Reflecting the recent emergence of 'precision mental health' - a person-centered approach to identifying, preventing, and treating psychopathology - researchers have begun to document associations between heterogeneity in features of depression and individual differences in brain circuitry, most frequently in resting-state functional connectivity (RSFC).

METHODS

In this review, we present emerging work examining pre- and post-treatment measures of network connectivity in depressed adolescents; these studies reveal potential intervention-specific neural markers of treatment efficacy. We also review findings from studies examining associations between network connectivity and both types of depressive symptoms and response to treatment in adults, and indicate how this work can be extended to depressed adolescents. Finally, we offer recommendations for research that we believe will advance the science of precision mental health of adolescence.

RESULTS

Nascent studies suggest that linking RSFC-based pathophysiological variation with effects of different types of treatment and changes in mood following specific interventions will strengthen predictions of prognosis and treatment response. Studies with larger sample sizes and direct comparisons of treatments are required to determine whether RSFC patterns are reliable neuromarkers of treatment response for depressed adolescents. Although we are not yet at the point of using RSFC to guide clinical decision-making, findings from research examining the stability and reliability of RSFC point to a favorable future for network-based clinical phenotyping.

CONCLUSIONS

Delineating the correspondence between specific clinical characteristics of depression (e.g., symptoms, severity, and treatment response) and patterns of network-based connectivity will facilitate the development of more tailored and effective approaches to the assessment, prevention, and treatment of depression in adolescents.

The Beijing Twin Study (BeTwiSt): An Update

The Beijing Twin Study (BeTwiSt), which was established in 2006, is an ongoing study aiming to investigate the genetic and environmental etiology of adolescent psychopathology. Resting-state brain imaging datasets have been examined for same-sex twins, and other psychological traits and emotional and behavioral variables have been examined for all twins. Based on the registry, the main findings regarding the etiological mechanism underlying adolescent development, magnetic resonance imaging results, and genetic and environmental influences on other psychological traits have been published. This article summarizes the key findings in these three areas and discusses future plans for the BeTwiSt.

Time-varying associations of parent-adolescent cultural conflict and youth adjustment among Chinese American families

The purpose of this study was to examine time-varying associations of parent-adolescent cultural conflict with depressive symptoms and grade point average (GPA) among Chinese Americans from ages 11-22. We pooled two independently collected longitudinal data sets (N = 760 at Wave 1) and used time-varying effect modeling (TVEM) to show that the frequency of parent-adolescent conflict increased during early adolescence (12 years), peaked at mid adolescence (16 years), and gradually decreased throughout late adolescence and young adulthood. In general, parent-adolescent conflict was associated with negative adjustment (more depressive symptoms and lower GPA) more strongly during mid- to late-adolescence (15 to 17 years) compared with other developmental periods. These time-varying associations differed slightly by gender, at least for GPA. Our findings provide important developmental knowledge of parent-adolescent conflict for Chinese American youth and suggest that attention to conflict and links to adjustment is especially relevant during mid to late adolescence. Our study also illustrates the usefulness of integrative data analysis and TVEM to investigate how the strength of conflict-adjustment associations might change throughout development. (PsycINFO Database Record