Adolescent brain development

17 July 2023


Adolescent brain development – what we know and what it means for policy

Reported by Blanca Piera Pi Sunyer, PhD Student, Department of Psychology

On 29 June, Professor Sarah-Jayne Blakemore, Professor of Psychology and Cognitive Neuroscience at the University of Cambridge, gave a lecture on adolescent brain development – what we know and what it means for policy. The lecture took place at Trinity College, Cambridge.

Professor Blakemore started her talk with a teenager’s diary entry from July 1969, illustrating adolescence (10 to 24 years) as a period of life when our sense of self undergoes profound development, and we try to establish ourselves in the outside world. She continued by discussing ways in which adolescent-typical behaviours are historically depicted and are observed in other species, highlighting that these typically occur in the presence of peers. Professor Blakemore suggested that engagement in risky behaviours by adolescents, for example smoking, drinking or drunk driving, might be explained by an adapted need to be included by the social group: avoiding social risks, such as being rejected or excluded from a peer group, might matter more to young people than other risks, such as health risks.

Social influence as a tool for education campaigns and policy interventions

Professor Blakemore suggested that heightened susceptibility to social influence from peers can be a useful framework to empower young people to have an active role in education campaigns or policy interventions. Within this context, Professor Blakemore informed the audience that research has shown that anti-bullying, anti-smoking and healthy eating campaigns have been highly effective when these have been led by young people, and particularly young people who were highly connected in their social groups.

Brain development in the context

Professor Blakemore explained that the sophistication of neuroimaging techniques has proven that adolescence is a period when the brain undergoes a significant restructuring of cortical and subcortical regions, as well as of the connectivity between different regions. She informed the audience that there are several microstructural explanations for these changes, which are all, in part, influenced by the environment in which the brain develops. Explaining that this brain reorganisation (or plasticity) can occur throughout the lifetime, Professor Blakemore also stated that there are periods in which different parts of the brain are particularly sensitive to their environment.

What factors in the environment might be risky?

Stating that depression, self-harm and anxiety disorders have increased in the past 15 years, Professor Blakemore asked what things in the environment have changed in the last 10 or 15 years that could be contributing to this risk. She then started talking about social media use, which has increased over the past years and emphasised that social media use is a difficult construct to measure, and its relationship to mental health might be (at least) bidirectional, which complicates any implications for policy. Nonetheless, Professor Blakemore discussed that there might be some sensitive periods for social media use and mental health, such as puberty when neuroplasticity is heightened.

Implications for education and for digital media use

At the end of the seminar, a question and answer session was held with audience participation. A question from the audience prompted a discussion about abolishing GCSCs in the UK education system. Professor Blakemore explained that GCSCs may no longer provide a useful qualification at a younger age and emphasised the evidence from NHS surveys, which suggest that most young people find academic and exam stress among the top stressful aspects of their lives. Professor Blakemore concluded the discussion by questioning whether we need to fill young people’s minds with short-term retention of information, in a period when we are better at divergent thinking and when young people are at peak vulnerability for developing mental health disorders.

Another question started a discussion about social media use and its relationship to vulnerability during adolescence. Professor Blakemore argued the role of puberty and social influence, as well as social transitions to secondary school and higher education, in conferring different forms of vulnerability during this period. Lastly, Professor Blakemore talked about obstacles that social media researchers encounter including accurately understanding social media use from the perspective of young people, and restrictive policies of big tech companies that limit collaboration with researchers.

Banner image by Milad Fakurian - Unsplash