Developmental and contextual considerations for adrenal and gonadal hormone functioning during adolescence: Implications for adolescent mental health

Abstract

Substantial research has implicated the hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonadal (HPG) axes independently in adolescent mental health problems, though this literature remains largely inconclusive. Given the cross-talk between the HPA and HPG axes and their increased activation in adolescence, a dual-axis approach that examines both axes simultaneously is proposed to predict the emergence and persistence of adolescent mental health problems. After briefly orienting readers to HPA and HPG axis functioning, we review the literature examining associations between hormone levels and changes with behavior during adolescence. Then, we provide a review of the literature supporting examination of both axes simultaneously and present the limited research that has taken a dual-axis approach. We propose future directions including consideration of between-person and within-person approaches to address questions of correlated changes in HPA and HPG hormones. Potential moderators are considered to increase understanding of the nuanced hormone-behavior associations during key developmental transitions.

Keywords: HPA axis; HPA-HPG associations; HPG axis; adolescence; cortisol; dehydroepiandrosterone; development; family context; hormone-behavior associations; testosterone.

FIGURE 1

Simplified diagram for the synthesis of cortisol, DHEA, and testosterone. All three steroid hormones are synthesized from cholesterol. Cholesterol is converted to pregnenolone, which is in turn converted to either progesterone or to 17α-hydroxypregnenolone, and so forth. Metabolism pathways within the hashed box occur in the gonads and metabolism of hormones within the solid box occur in the adrenal cortex. Model adapted primarily from Payne and Hales (2004) and Heikkilä (2002).

FIGURE 2

Interaction of the HPA and HPG axes in adulthood. Solid lines represent stimulating pathways and hashed lines representing inhibitory pathways. Note that estradiol can provide both positive and negative feedback at different phases of the menstrual cycle. Model adapted primarily from Stratakis and Chrousos (1995) and Terberg et al. (2009).

FIGURE 3

Conceptual model of hormone–behavior associations and adolescent mental health over time. The hormonal milieu is depicted across the top of the Figure as a combination of HPA axis (solid box), HPG axis (hashed box), and interactions of HPA and HPG axis hormones, which can be conceptualized in terms of basal levels, diurnal changes, or stress responsivity (depicted in circles within the boxes), each of which undergoes developmental shifts (depicted as the block arrow labeled Development), and are influenced by genes and can influence gene expression (depicted by the bidirectional arrow from genetic influences to the hormonal milieu). Note that genetic influences are depicted as a single circle because the structure of DNA does not change over time, although genetic expression and influences certainly do change over time. Basal levels, diurnal changes, and stress responsivity of HPA, HPG, and across HPA and HPG hormones are all associated with adolescent emotion and behavior problems (depicted as bidirectional arrows). These associations are also thought to be context dependent (depicted by the bidirectional arrows passing through a semi-transparent arrow depicting changing environmental context over time).