The Connection Between Childhood Bullying, Depression, and Genetics  

Bullying is an unpleasant human behavior that everyone knows and understands. Most of us associate bullying with childhood and elementary school.  But as we know, bullies don’t always go away after elementary school. Some keep it up in middle school and high school, and some persist with their bullying behavior well into adulthood. Fortunately, one thing we learn in middle school and high school is how to deal with bullies. Our parents teach us they’re probably lashing out at what they don’t understand. They teach us people attack what they fear. They tell us it’s likely those kids have trouble at home or have been bullied themselves at some point in their lives.

Anyway, in most cases, bullies outgrow their bullying behavior.

And in most cases, people who experience bullying learn to handle it. They shouldn’t have to, yet they have no choice – so they handle it. They get help from adults, who teach them to process their emotions, rebuild their self-esteem, and move on with the business of being a child.

For some, however, the effect of bullying lingers.

The bully may grow, mature, and move beyond the bullying, and others who were bullied by that person may likewise move on and put the unpleasantness in the past.

Unfortunately, while those people put bullying in the rear-view mirror, there’s a group of kids for whom bullying has long-lasting effects.

For those kids, being bullied as a child can lead to depression as a young adult.

Researchers have worked for years to identify the factors that may cause certain bullied kids to develop depression and others to avoid depression altogether. A new study published this year in the U.K. sheds light on this topic.

Hint: family history may play a larger role than previously thought.

The Avon Study: Children of the 90s

First, we’ll offer some details about this research effort.

The publication on bullying is a small part of something bigger: a large-scale, longitudinal cohort study that began in 1990 called the Avon Longitudinal Study of Parents and Children (ALSPAC).

Quick note, so we’re all on the same page: large-scale, longitudinal cohort study means researchers found a lot of experimental subjects (9,394 people), grouped them together by type (in this case, parents and children – that’s the cohort part), and collected information from them over a long period of time (that’s the longitudinal part).

The Avon Study has collected close to thirty years of data on parents and children. This report – “Genetic and Environmental Risk Factors Associated With Trajectories of Depression Symptoms From Adolescence to Young Adulthood” – examined 3,525 individuals age 10-24 to determine whether they had developed depression, and if so, why.

Here’s what they found:

  • Depression in individuals age 10-24 followed five distinct trajectories:
    • Stable-low. These individuals showed consistent, low levels of depressive symptoms.
    • Early-adult-onset. These individuals started with low-level symptoms that increased during adolescence and early adulthood.
    • Adolescent­-limited. These individuals experienced depressive symptoms during adolescence only.
    • Childhood- These individuals experienced elevated depressive symptoms during childhood, which decreased toward adolescence.
    • Childhood- These individuals experienced moderate depressive symptoms during childhood, which increased – and stayed elevated – during adolescence and early adulthood.
  • Researchers identified data associating both genetic and environmental risk factors with all five trajectories of depression:
    • A primary genetic risk factor across all trajectories is a family history of depression
    • A primary environmental risk factor across all trajectories is experiencing childhood bullying
  • Researchers found strong associations between a family history of depression and:
    • Childhood-persistent depression
    • Early-adult-onset depression
  • Researchers found strong associations between experiencing childhood bullying and:
    • Childhood-limited depression
    • Childhood-persistent depression

Let’s take a closer look at those results.

Inside the Data: Multiple Risk Factors Increase Vulnerability

Researchers found something interesting: individuals on the childhood-persistent depression trajectory showed a strong association with both risk factors: genetic and environmental.

As noted above, characteristics of childhood-persistent depression include mild depressive symptoms early in life, followed by escalating symptoms during adolescence and early adulthood. Therefore, this data means that individuals with a family history of depression (the genetic risk factor) who experience bullying as children (the environmental risk factor) are at increased risk of developing depression that escalates – and remains at elevated levels – through adolescence and into adulthood.

In contrast, individuals who experienced childhood bullying but did not have a family history of depression showed fewer depressive symptoms in early adulthood.

This is a new insight into the complex combination of factors that contribute to the development of depression during adolescence and early adulthood.

Now that we have this information, how can we use it?

Targeted Interventions

In an interview with Science Daily, Dr. Rebecca Pearson, a lead author on the study, discusses the relevance and potential applications of this wrinkle in the research:

“The results can help us to identify which groups of children are most likely to suffer ongoing symptoms of depression into adulthood and which children will recover across adolescence. For example, the results suggest that children with multiple risk factors (including family history and bullying) should be targeted for early intervention but that when risk factors such as bullying occur in isolation, symptoms of depression may be less likely to persist.”

 This is important advice for anyone who works with children: teachers, social workers, school administrators, coaches, and, of course, parents. It gains further salience when considered in light of recent research identifying bullying as an Adverse Childhood Experience, or ACEs. Individuals exposed to ACEs are at higher risk of developing a host of chronic physical conditions, and are particularly vulnerable to developing mental health disorders.

[For more information on ACEs, read our articles here and here]

With that said, it’s important to understand that exposure to an ACE does not mean an individual will develop chronic physical and mental health issues – it simply increases the risk. Children with the support of a qualified adult can process the toxic stress associated with ACEs and mitigate its long-term effects.

The same is true with the depression risk factors discussed above: a family history of depression and experiencing bullying as a child do not mean an individual will develop depression – those factors simply increase the risk. As with ACEs, adults can help children process the toxic stress associated with bullying, thereby decreasing the likelihood they’ll develop depression. And if they do begin to show symptoms of depression, they can learn to manage and mitigate those symptoms with the help of mental health professionals.

Takeaways for Parents

One thing is clear: if depression runs in your family and your child experiences bullying at school, the prudent course of action is to seek some form of professional support for your child. That course of action is prudent whether your child has developed depressive symptoms or not. A conversation with a mental health professional can help you determine if a full psychological assessment is warranted, and an assessment from a licensed mental health professional can determine if your child meets the criteria for or shows the initial signs of clinical depression.

The sooner you have that conversation or get that assessment, the better: research shows that the earlier an individual receives support after receiving a diagnosis for a mental health disorder, the more likely they are to successfully manage the symptoms of that disorder. On the other hand, if you arrange that conversation or assessment and a qualified professional concludes your child does not need an assessment and/or does not meet the criteria for clinical depression, that’s one less thing for you to worry about – and you and everyone in your family can proceed with life as planned.

If you think your child is at risk, you can find a qualified professional in your area with this psychiatrist finder provided by the American Academy of Child and Adolescent Psychiatry.