One of the great questions in the addiction field is why do some people become full-blown addicts while other people can use drugs occasionally without progressing to anything more serious? One part the answer definitely has to do with the drug itself. For example, heroin causes a more intensely pleasurable high than cocaine and people that try heroin are more likely to become addicted to it than cocaine. But that’s not the whole story.

I’ve written previously about how a negative, stressful environment can have long-lasting negative impacts on the development of a child’s brain (also known as early-life stress of ELS). ELS such as childhood abuse (physical or sexual) and neglect can increase the risk for a whole host of problems as an adult such as depression, bipolar disorder, PTSD, and of course drug and alcohol abuse. There’s even a risk for more physical ailments like obesity, migraines, cardiovascular disease, diabetes, and more.

Childhood abuse/neglect = psychological and physical problems as an adult.

This idea doesn’t sound too controversial but believe it or not, the idea that a bad or stressful situation as a child would do anything to you as an adult was laughed away as not possible. It’s only within the last decade or so that a wealth of research has supported this idea that ELS can physically change the brain and that these changes can last through the abused child’s entire life.

This recent review paper (published in the journal Neuron) is an excellent, albeit technical, summary of dozens research papers done on this subject and the underlying biology behind their findings.

I especially love the quotes the author included at the beginning of the article:

And even more recently, yet another research paper has come out that highlights how important childhood is for the development of the brain and how a stressful childhood environment can impact the function of a person as an adult.

This most recent report, published in the journal Neuropscyhopharmacology concludes that early childhood abuse affects male and females differently. That is to say that the physical changes that occur in the brain are distinct for men and women who were abused as children.

Studies like this one are done by examining the brains of adults who were abused as kids and then comparing the activity or structure of different parts of the brain to the brains of adults who were not abused. The general technique of examining the structure or activity of the brain in a living human being is called neuroimaging and includes a range of techniques such as MRI, PET, fMRI, and others. (I’ve written about some of these techniques before. In fact, the development of better methods to image the brain is a huge are of research in the neuroscience field).

However, this study did not examine behavioral differences in the subjects, but as I said above, a great number of many other studies have looked at the psychological consequences of ELS. But this paper is really primarily interested in the gender differences in the brains of adults that have been abused as kids.

*Note: the following discussion is entirely my own and is not mentioned or alluded to by the author’s of this study at all.

This work—and the many studies that preceded it—has important implications because as a society, we have to realize that part of our personality/intelligence/character/etc. is determined by our genetics while the other part totally depends on the environment we are born into. I don’t want to extrapolate too much but the idea that childhood abuse can increase the risk of psychological problems as an adult also supports the broader notion that a great deal of a person’s success is determined by entirely random circumstances.

The science shows that a child born into a household rife with abuse will have more chance of suffering from a psychological problem (such as addiction) as an adult than someone who was born into a more stable life. The psychological problem could hurt that person’s ability to study in school or to hold down a job. And the tragic irony, of course, is that no child gets to choose the conditions under which they are born. A child, born completely without a choice of any kind over whether or not he or she will be abused, can still suffer the consequences of it (and blame for it) as an adult.

As a society, we often always blame a person’s failures as brought on by his or her own personal failings, but what if a person’s childhood plays an important role in why that person might have failed? How, as a society, do we incorporate this information into the idea of ourselves as having complete control over our minds and our destinies, when we very clearly do not? As an adult, how much of a person’s personality is really “their own problem” when research like this clearly show that ELS impacts a person well after the abuse has ended?

If the environment a child is born into has a tangible, physical effect on how the brain functions as an adult, than this problem is more than a social or an economic one: this is a matter of public health. Studies that support findings such as these provide empirical significance for public policy and public services for child care such as universal pre-K, increased availability of daycare, health insurance/medical access for children, increased and equitable funding for all public schools regardless of the economic situation of the district that school happens to be located in, etc.

One of our goals as a society (if indeed we believe ourselves to be a functioning society…the success of Donald Trump’s candidacy raises some serious doubts…but I digress) is the improvement of the lives of ALL of our citizens and securing the prosperity of the society for future generations. Reducing childhood poverty and abuse quite literally could help secure the future generations themselves and improve the ability of any child to grow up to become a successful and productive adult.

Public programs are essential because the unfortunate reality for many people born into poverty is that they must work all the time at low paying jobs in order to simply survive and may not be able to give their children all the advantages of a wealthier family. And this is where government and public policy step in, to correct the imbalances and unfairness inherent to the randomness of life and level the playing field for all peoples. Of course, the specific programs and policies to reduce childhood poverty and abuse would need to be evaluated empirically themselves to guarantee an important improvement in development of the brain and health of the child when he/she grows up.

And this is the real power of neuroscience and basic scientific research papers like this one. Research into how our brains operate in real-life situations reveal a side of our minds and our personalities that we never may have considered before and the huge implications this can have for society. The brain is a complex machine and just like other machines it can be broken.

Of course, we shouldn’t extrapolate too much and say that, for example, a drug addict who was abused as a child is not responsible for anything they’ve ever done in between. But is important to recognize all the mitigating factors at play in a person’s success and simply dismiss someone’s problems as “their own personal responsibility.” As a neuroscientist, I might argue that that phrase and the issues behind it are way more nuanced than the how certain politicians like to use it.

Special endnote Due to some recent shifts in my career, Dr. Simon Says Science will be expanding the content that I write about. Addiction and neuroscience will still be prominently featured but I plan to delve into a variety of other topics that I find interesting and sharing opinions that I think are important. I hope you will enjoy the changes! Thanks very much!