The Adolescent Brain and Mental Health

By Stephanie Blay Muah, BSc Neuroscience, University of Lethbridge

The formative years of adolescence are critical for the development of interpersonal or social skills and psychological behaviours essential to positive mental health. As recently as a few decades ago, it was still thought that the brain only grew and developed during childhood and did not change much after that. However, newer brain imaging studies show that the brain does in fact mature past childhood and that these changes continue well into the twenties and thirties (UCL, 2022). Adolescence is a time when mental health challenges are more likely to occur, and these may have permanent negative effects on the brain.

 Teenagers' mental health can be negatively impacted by several risk factors. Experiencing difficulties, feeling compelled to fit in with classmates, and exploring one's individuality are all events that may contribute to stress during adolescence. The gap between an adolescent's life as it is now and their beliefs or hopes for the future can be threatened by media and gender stereotypes. The quality of family environment and connections with peers are also important factors that influence mental health during adolescence. Childhood trauma, for example any form of sexual assault, and serious socioeconomic issues also have an impact.

There are several changes that occur in the brain of an adolescent. One is neuroplasticity. Neuroplasticity refers to the physiological changes in the brain that happen as the result of our interactions with our environment. From the time the brain begins to develop in utero until the day we die, the connections among the cells in our brains reorganize in response to our changing needs. This dynamic process allows us to learn from and adapt to different experiences (Celeste Campbell n.d.). An adolescent suffering from a mental health challenges such as depression may find themselves losing interest in anything and feeling sad.  This is because the brain regions that are involved (the hippocampus, the amygdala and the dorsomedial thalamus) all are having trouble forming new connections between themselves.

Another change that occurs in the brain of an adolescent suffering from mental health challenges is amygdala hyperactivity due to trauma such as a post-traumatic stress disorder (PTSD) and as a result, the individual is unable or has difficulty controlling their emotions. Chronic stress can be another factor. Prolonged stress can cause the hippocampus to shrink, which can impair memory, as well as other anatomical changes in the brain. Uncontrollable stress has been recognized to influence the hippocampus at various levels of analysis. Behaviorally, human and animal studies have found that stress generally impairs various hippocampal-dependent memory tasks (Kim et al., 2015).

Furthermore, during adolescence, the grey matter of the brain (where the nerve cells sit) is slowly shrinking, while white matter (the wiring between nerve cells) is still growing. These changes in the brain indicate that the neural networks are further refining their functions and connections, getting rid of what is irrelevant and reinforcing what is important. Scientists believe that a driving factor of this change is the growth of myelin. Myelin is a fatty substance that insulates the connections between cells and leads to better transmission of information.

These changes are more accentuated in some areas of the brain than others, namely the ones hosting the higher-order cognitive functions. The prefrontal cortex, in particular, shows the most protracted development, lasting well into a person’s twenties. This is the part of the brain that hosts our most sophisticated abilities – from making complex decisions to planning and suppressing unwanted urges. Moreover, we found that this reduced myelin growth was actually directly related to the worsening of mental health symptoms over time (UCL, 2022).

In conclusion, adolescence is a crucial age when individuals tend to undergo a lot of stress knowingly or unknowing and it can take a toll on them. During this period, adolescents need supportive parenting and positive peer influence. If you are struggling with mental health issues or know of someone who could use support, visit https://www.canada.ca/en/public-health/services/mental-health-services/mental-health-get-help.html or Southern Alberta, https://www.albertahealthservices.ca/findhealth/Service.aspx?id=6810&serviceAtFacilityID=1047134

References

Campbell, C. (2009). What is neuroplasticity?BrainLine. Retrieved from https://www.brainline.org/author/celeste-campbell/qa/what-neuroplasticity.

Kim, E. J., Pellman, B., & Kim, J. J. (2015). Stress effects on the hippocampus: a critical review. Learning & memory (Cold Spring Harbor, N.Y.), 22(9), 411–416. https://doi.org/10.1101/lm.037291.114

U. (2022b, May 6). Analysis: Teenage mental health - how growing brains could explain. UCL News. https://www.ucl.ac.uk/news/2021/mar/analysis-teenage-mental-health-how-growing-brains-could-explain-emerging-disorders

Photo: https://innohealthmagazine.com/2020/issues/covid-19-and-its-impact-on-adolescent-mental-health/