I previously wrote a column in which I discussed the possible relationship between television viewing and the risk of developing depression. In that column I mentioned that, while there is widespread suspicion that depression may have a genetic component, I was unaware of any strong evidence that this is the case. This week I encountered another study in the American Journal of Psychiatry that suggests that the environment in which a child is raised can play a significant role in whether he or she will develop depression.
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All of the children in the study had been born to families in which at least one biological parent had been diagnosed with major depression. There were nearly 700 full sibships and 2,600 half sibships studied. The researchers found that children who had been adopted away and raised in families that had been selected for having high-quality childrearing standards were significantly less likely to develop depression (23% for full siblings, 19% for half siblings) than their siblings who had remained in the home of their biological parents. It is interesting that this protective effect of the adoptive home “disappeared when an adoptive parent or stepsibling had major depression or the adoptive home was disrupted by parental death or divorce.”
It is unlikely that this study ever will be replicated because of the unique manner in which these Swedish adoptions were managed and recorded. However, and probably even more of an influence than genetics.
Are you surprised by the results of this study? Or, like me, have you always suspected that a child growing up in a household with a depressed, missing, or divorced parent was at increased risk of becoming depressed, particularly they had a genetic vulnerability? How will you change your approach to families with a depressed parent or ones that are navigating through the stormy waters of even an amicable divorce? Will you be more diligent about screening children in these families for depression? Should the agencies that are responsible for managing adoption and foster home placement include this new information in their screening criteria?
Dr. William G. Wilkoff
It would be very interesting to see a similar study performed using families in which a biological parent had been diagnosed with anxiety or an attention-deficit disorder. Could it mean that we should be considering depression and these conditions as contagious disorders? The results from such studies might help provide clarity to why we are seeing more children with mental health complaints. They might explain why pediatricians are seeing an increasing frequency of mental health complaints in our offices. It may not be too far-fetched to use epidemiologic terms when we are talking about depression, anxiety, and ADHD. Should we be considering these conditions to be contagious under certain circumstances?
Since the human genome has been sequenced I sense that our attention has become overfocused on using what we are learning about our DNA to explain what makes us sick. It may be time to swing the pendulum back a few degrees and remind ourselves of the power of the family environment.
Dr. Wilkoff practiced primary care pediatrics in Brunswick, Maine, for nearly 40 years. He has authored several books on behavioral pediatrics, including “How to Say No to Your Toddler.” Email him at pdnews@mdedge.com.