A risk factor for mental health disorders, childhood abuse must stop
06th April 2017
06th April 2017
Mental health disorders are largely present in our lives as they affect approximately 1 in 4 people worldwide. Depression is the most predominant mental health disorder and it is estimated that more than 300 million people suffer from it. Depression is a major contributor to the burden of suicide, which in turn is a leading cause of death in 15-29-year-olds.
In the field of mental health, this has meant much effort and thousands of millions invested in genetic studies during the last few decades. Highly sophisticated and pioneering technology has been developed to unravel the genetic basis of mental disorders. Results[1], however, have been disappointing as they showed that mental disorders cannot be explained solely on the basis of genes. So something else was added to the equation, and it was not something new: the environment.
The “gene-environment[2]” approach rescued the long-standing idea that genes confer a certain vulnerability to illness, which needs the action of an environmental insult to manifest itself. This approach was largely welcomed by policies and funding agencies, and a lot has been invested to better understand the intimate relationship between these two mental disorder influencers.
Let me go into a little more detail here about what is meant by “environmental insult”[3]. This term is used to refer to any life event that may be stressful enough to be considered capable of having serious consequences in the life of a person. These events might include physical and emotional abuse and neglect, bullying and domestic violence, and poverty. As mental health disorders are supposed to have a developmental component, many studies have explored “early-life environmental insults”, which translates into experiences of abuse and neglect during childhood.
Hence, many gene-environment studies have explored the following question: Does a person’s genetic background predict the development of a mental disorder, given that this person has suffered childhood abuse?[4] The ensuing results confirmed expectations. But the conclusions given were surprising to say the least.
Two important messages emerged from these gene-environment studies. First, childhood abuse is a central risk factor for the development of a mental health disorder, estimated to increase the chances of developing depression later in life by 2-4 times.[5] Second, some genetic variants add to this risk such that some people may be even more vulnerable to the detrimental impact of childhood abuse. As I said, these results are not surprising at all.
But proposals for future work were simply extraordinary, if not alarming.
Experts proposed that the next obvious step was to build further sophisticated technology so anyone can know if they have the “vulnerability genes”. Many of them even visualised the society of the future as a time where genetic background could be modified so these people won't be affected by environmental insults such as childhood abuse.
I’m not joking. I took an active part in these discussions and my account is 100% true. And it's not funny at all.
After years of research and millions invested, the evidence was yelling the most obvious conclusion and recommendation: "stop childhood abuse". Even then, a tremendous body of experts, policy makers and funding agencies would not listen. Results were saying that prevention in mental health must focus, to a large extent, on stopping little children from being abused by their very relatives and teachers. That mental health policies must allocate resources to stop the humiliation, the injuries and the sexual abuse that little children are suffering today. Instead, efforts are directed at developing intricate techniques to build an aseptic society free of any genetically-derived vulnerability.
A similar comment can be made regarding the role that mental health disorders have relative to other non-communicable diseases in terms of public visibility and investment. Despite the fact that suicide is a leading cause of death among young people around the world, and that depression has been declared the largest cause of disability worldwide, mental health is still largely missing from the international agenda. With depression both a risk factor for other NCDs and existing as a comorbidity alongside other NCDs, failure to integrate and prioritise mental health protection is negligent in its own right.
Prevention strategies in mental health must aim to eradicate childhood abuse and neglect in any form. This is without a doubt a sensitive topic – it is not like encouraging planning departments to invest more in public transport so that people can be more active, or affixing gory images to cigarette packets and raising their prices to nudge smokers away from tobacco.
Childhood abuse, and the fact that it is happening much more frequently than we dare to admit, challenges our own perception of being a part of a well-groomed, highly organized society. But childhood abuse has harmful, long-lasting consequences in the health of the survivors. It is time to accept this reality and take action to end such environmental insults that have far and wide reaching ramifications on health.
Ximena Goldberg is a mental health researcher based in Barcelona, and the co-founder of Resilie (@Reslie_org) a non-profit that seeks to reduce the burden of mental health disorders among young people. Resilie takes a community-based approach to build resources for resilience and early identification of risk behaviours associated with mental health.
[1] Flint J & Kendler KS. The genetics of major depression. Neuron. 2014 Feb 5;81(3):484-503. doi: 10.1016/j.neuron.2014.01.027.
[1] Kahn et.al. Schizophrenia. Nat Rev Dis Primers. 2015 Nov 12;1:15067. doi: 10.1038/nrdp.2015.67.
[1] Otowa et.al. Meta-analysis of genome-wide association studies of anxiety disorders. Mol Psychiatry. 2016 Oct;21(10):1391-9. doi: 10.1038/mp.2015.197. Epub 2016 Jan 12.
[2] Caspi A., et al. (2003) Influence of life stress on depression: moderation by a polymorphism in the 5-HTT gene. Science, 301(5639), 386–389
[2] Caspi et al. Role of genotype in the cycle of violence in maltreated children. Science. 2002 Aug 2;297(5582):851-4.
[3] Mofit et al. Strategy for investigating interactions between measured genes and measured environments Arch Gen Psychiatry. 2005 May;62(5):473-81.
[4] Bellani et al, G × E interaction and neurodevelopment I. Focus on maltreatment. Epidemiol Psychiatr Sci. 2012 Dec;21(4):347-51. doi: 10.1017/S2045796012000418.
[5] This recent meta-analysis shows that childhood maltreatment increases 2-4 times the chances to have depression later in life