Childhood Deprivation Associated With Having Smaller Brains

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Neuroplasticity, the brain’s natural ability to continuously adapt and change in response to influences in our environment, sustains normal learning and development. It also encourages recovery of function after an injury or damage. At the same time, it can also leave our brain vulnerable to the negative effects of harmful psychosocial experiences, such as maltreatment. This might prove even more so during early childhood, which is a key life stage encompassing rapid and dynamic changes in brain structure and function that have been hypothesised to increase malleability to environmental influences. The following study provides evidence of a specific link between exposure to deprivation occurring only in early childhood and altered brain structure in young adulthood.

In the English and Romanian Adoptees (ERA) study, adoptees entered the orphanages in the early weeks of life, and then spent between 2 weeks and 43 months (3 years, 7 months) living there before being adopted into families in the United Kingdom that provided mostly nurturing environments. As a result, adoption established an extreme and sudden improvement in circumstances – especially when compared with the appalling conditions experienced in the institutions. In the institutions, children were regularly malnourished and had minimal social contact, with insufficient caregiving and very little cognitive stimulation due to a lack of toys and confinement to cots. The video below gives an account of these institutions.

The study was conducted to investigate if deprivation in early childhood was associated with alterations in the adult brain (young adult follow-up was recorded when participants were aged between 22 and 26 years). The sample was also categorised by duration of deprivation in order to allow for a test of the effects of deprivation “dose”, to make clearer the association between deprivation and brain outcomes.

This study used a whole-brain analysis strategy to first look at whether early institutional deprivation was linked with changes in total brain volume (TBV) in young adulthood. This was done by comparing Romanian adoptees with nondeprived UK adoptees. The results of the analysis showed that the group of institutionally deprived Romanian adult adoptees displayed an 8.57% reduction in TBV compared with the nondeprived group of UK adoptees. This study also investigated links with deprivation duration, with results showing that each additional month of deprivation there was associated with a 0.27% reduction in TBV. These results were similar for both total grey and white matter volumes (grey and white matter are the components of the brain and spinal cord, and they contain different parts of neurones).

Image 1: A; Graphs showing the distributions of TBV in deprived and nondeprived groups. As shown, there is an overall reduction in TBV in the deprived group.
B; Graph showing the link present between deprivation duration and TBV. As shown, there is a negative correlation between deprivation duration and TBV; so as deprivation duration increases, TBV decreases.

Furthermore, many individuals who spent an extended period (i.e. over 6 months) in the orphanages consequently displayed increased symptom rates of neurodevelopmental disorders, including attention deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and disinhibited social engagement (DSE; a pattern of indiscriminate friendliness toward strangers and lack of selectivity in attachment-related behaviours), which persisted in many individuals through to young adulthood.

This study provides evidence that severe deprivation in the first years of life is associated with intense and persisting changes in brain volume and structure in young adulthood. These changes were clearly detectable even when individuals exposed to this form of deprivation were then brought up in families that provided nurturing environments for the rest of their childhoods. These deprived adoptees not only had significantly smaller brains than their nondeprived counterparts, but the extent of reduction in TBV increased linearly with each additional month of deprivation.

Sources Used:

Original Paper: Mackes, NK., Golm, D., Sarkar, S., et al., (2020) “Early childhood deprivation is associated with alterations in adult brain structure despite subsequent environmental enrichment.” PNAS. DOI: 10.1073/pnas.1911264116

Original Link: https://www.pnas.org/content/117/1/641

Video 1: Growing up in a Romanian orphanage – BBC News. Youtube.com. https://www.youtube.com/watch?v=VCeWr8OFuEs

Image 1: https://www.pnas.org/content/117/1/641

Featured Image: Photo by Sl Wong, from Pexels.

Edited by Cyrus Rohani-Shukla

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