Problems with 'Pruning' Brain Connections Linked to Adolescent Mental Health Disorders
Published:29 May2023 Source:University of Cambridge
Problems with the brain's ability to 'prune' itself of unnecessary connections may underlie a wide range of mental health disorders that begin during adolescence, according to research published today. The findings, from an international collaboration, led by researchers in the UK, China and Germany, may help explain why people are often affected by more than one mental health disorder, and may in future help identify those at greatest risk.
The team examined data from 1 750 adolescents, aged 14 years, from the IMAGEN cohort, a European research project examining how biological, psychological, and environmental factors during adolescence may influence brain development and mental health. Adolescents who experienced mental health problems -- regardless of whether their disorder was one of internalising or externalising symptoms, or whether they experienced multiple disorders -- showed similar patterns of brain activity. These patterns -- the NP factor -- were largely apparent in the frontal lobes, the area at the front of the brain responsible for executive function which, among other functions, controls flexible thinking, self-control and emotional behaviour.
When the team looked at genetic data from the IMAGEN cohort, they found that the NP factor was strongest in individuals who carried a particular variant of the gene IGSF11 that has been previously associated with multiple mental health disorders. This gene is known to play an important role in synaptic pruning, a process whereby unnecessary brain connections-synapses-are discarded. Problems with pruning may particularly affect the frontal lobes, since these regions are the last brain areas to complete development in adolescents and young adults.