The effect of sex hormones on brain development and functioning

Abstract

The human brain continues to develop and change throughout life. Structural and functional studies research helps us to understand that the brain matures through gestation, infancy, childhood, adolescence and into young adulthood up until the mid to late twenties (Kolb and Whishaw, 2015). Healthy brain maturation during childhood and adolescence supports learning through these years and is considered essential for normative cognitive, social, and emotional development, setting the scene for a healthy, positive adulthood. Puberty is a key stage in development involving a complex cascade of hormonal changes, particularly those identified as sex hormones (androgens and estrogens) and the hypothalamic and pituitary hormones that control their release. Although most often researched in relation to puberty, the effect of sex hormones on our bodies and brains begins in utero and continue throughout our life. Despite the clear overlap in timing of brain development and the fluctuation of hormones throughout the first 20years of our life, research investigating the association between the two from a developmental point of view is much less well developed than might be expected. This chapter will provide a brief review of brain development including in utero maturation through to adolescence and discuss the simultaneously occurring sex hormone changes occurring throughout this period. Following this, we present a review and critique of the literature investigating the role of sex hormones on brain development and functioning across both animal and human studies and examine how this links with adolescent brain development and the associated changes in neurocognitive functioning. Finally, we provide a case study to illustrate the potential relevance of these findings to modern clinical practice.