Early adversity in the form of neglect, physical, sexual and emotional abuse, low socio-economic environmental factors and adverse life events have all been proven to contribute to long term health and developmental problems in children. The severity of negative psychological impacts and broad ripple effects make childhood adversity a significant public health concern.

Social economic status (SES) is a key metric which can determine the likelihood of psychological problems. Upbringing in low socio-economic conditions generally increases risk of exposure to adverse life experiences, with greater likelihood of corresponding low-quality parenting, poor healthcare and education. Cognitive aptitude tests have revealed that there is a consistent disparity in test results between children in the top and bottom SES brackets. At 22 months of age the spread is approximately 13% and this widens to 28% by ten years of age (Leon Feinstein 2003). Genetic influence has proven that monozygotic twins share an 81% test result correlation at age 3 months increasing to 88% by 15 years. For dizygotic twins the correlation is 73% and 54% respectively. Twins separated at birth reflect the impact of socio-economic status on cognitive performance, demonstrating that SES has a profound effect on test results regardless of genetic influence (Pedersen et al 1985).

Extensive research was carried out into the impact of early life adversity by following children raised from birth in orphanages in Romania and later adopted in England. This was a study into the impact of institutional deprivation which was proven to have rather alarming effects on the psychological development of the children involved. The study showed that depravation of basic nurturing necessities, namely lack of social, emotional and cognitive stimulation as well as lack of attachment availability, had broad negative impacts across psychological functions from IQ, autism spectrum disorder risk, hyperactivity and inattentiveness, social inhibition, conduct disorders and emotional dysfunction (Sonuga-Barke et al 2017). It also demonstrated importance of attachment in the early period of development. As follow up studies many years down the line proved that lack of attachments during earlier life make later life relationships more arduous.

Childhood physical abuse is the second most common type of child maltreatment after neglect and is associated with a broad repertoire of mental health problems. In particular ADHD, post traumatic stress disorder and bipolar disorder (Sugaya et al 2012). It also increases the risk of suicide and disorders such as major depression, conduct disorder, ODD, anxiety and substance misuse.

If a child is subjected to one form of adversity, there is a very good chance that he/she will also experience at least one other co-occurring adverse condition. With the correlation ranging from 81-98% (Dong et al 2004). This highlights the interrelatedness of childhood adversities and makes the psychological impact of a single type of adverse experience difficult to interpret and measure.

On a neurological level, gross anomalies in the function of specific regions of the brain can be observed in children that have been subjected to severe neglect. These include the amygdala, hippocampus, orbitofrontal gyrus and prefrontal cortex, which are areas important for emotional and stress regulation as well as executive decision. Impairments in these regions are frequently associated with a broad range of mental health problems, thus there are clear links between the behavioural manifestations symptomatic of psychological problems and childhood neglect as evidenced by these biological observations. Furthermore, severe neglect causes a disruption of hormonal balance of oxytocin and vasopressin which are vital to normal social and emotional function as both play a part in activating the dopaminergic reward pathway in response to social cues (Strathearn L. 2011).

Postpartum depression (PPD) and depression during pregnancy in mothers has been shown to have adverse impact on the child’s mental health. PPD can affect the normal bonding patterns between mother and child. The mother may experience abnormal thought processes such as lack of interest in her child and may act in erratic ways which are not conducive to positive nurturing behaviours and can in fact stress the child (Rifkin-Graboi et al 2013). Children born to mothers who experienced depression during pregnancy have a higher risk of depression and those born to mothers who have PPD have a greater disposition to emotional and behavioural problems, both of which are attributed to a combination of genetic and environmental factors, which display alterations in amygdala function in brain scans (Rifkin-Graboi et al 2013).

Early adversity in its myriad of forms clearly plays a crucial role in the development of psychological problems. Twin studies have been pivotal in distinguishing the impact of nurture vs nature and the neuroscientific findings have given focus to the likely regions affected by such adversities.

 

Child-to-adult neurodevelopmental and mental health trajectories after early life deprivation: the young adult follow-up of the longitudinal English and Romanian Adoptees study (2017). Edmund J. S. Sonuga-Barke, Mark Kennedy, Robert Kumsta, Nicky Knights, Dennis Golm, Michael Rutter, Barbara Maughan, Wolff Schlotz, Jana Kreppner. Lancet 2017; 389: 1539–48

Inequality in the Early Cognitive Development of British Children in the 1970 Cohort (2003). Leon Feinstein. Economica (2003) 70, 73-97

Separated Fraternal Twins: Resemblance for Cognitive Abilities (1985). N. L. Pedersen, G. E. McClearn, R. Plomin, L. Friberg. Behavior Genetics, Vol. 15, No. 4, 1985

Sugaya, L., Hasin, D. S., Olfson, M., Lin, K. H., Grant, B. F., & Blanco, C. (2012). Child physical abuse and adult mental health: a national study. Journal of traumatic stress, 25(4), 384–392. doi:10.1002/jts.21719

The interrelatedness of multiple forms of childhood abuse, neglect, and household dysfunction (2004).Dong M, Anda R.F., Felitti V.J., Dube S.R., Williamson D.F., Thompson T.J., Loo C.M., Giles W.H. Child Abuse and Neglect. 2004 Jul; 28(7):771-84.

Prenatal Maternal Depression Associates with Microstructure of Right Amygdala in Neonates at Birth (2013). Anne Rifkin-Graboi, Jordan Bai, Helen Chen, Waseem Bak’r Hameed, Lit Wee Sim, Mya Thway Tint, Birit Leutscher-Broekman, Yap-Seng Chong, Peter D. Gluckman, Marielle V. Fortier, Michael J. Meaney, and Anqi Qiu. Biological Psychiatry, Volume 74, Issue 11 (December 1, 2013)

Maternal neglect: oxytocin, dopamine and the neurobiology of attachment (2011). Strathearn L. Journal of neuroendocrinology, 23(11), 1054–1065.