Why Would Breastfed Children Be Less Depressed?

I had an interesting call this week from a reporter. A new study is being released showing that children who were breastfed for 6 months or longer were significantly less likely be depressed several years later. Did I have any ideas about why they might have found that?

Actually, I did. It all comes back to the human stress response.

We know from a number of different studies that women who breastfeed past six months are doing a lot of things differently than women who stop in the first few weeks. For example, women who are still breastfeeding at six months are more likely to sleep near their babies, increasing the ease of nighttime breastfeeding while also sustaining their milk supply. These mothers are more likely to practice babywearing, or carrying their babies on their bodies rather than in a carseat or stroller. Finally, they are more likely to breastfeed their babies on cue rather than according to a schedule.

It's this total constellation of behaviors that sustains breastfeeding past the first few days and weeks, and I believe it accounts for the lower rates of depression among breastfed children. This pattern of behavior increases mothers' responsiveness to their babies, which lowers babies' stress levels. That is the key to understanding their lower risk.

When babies are ignored, or left to cry it out, their stress levels rise. If this only happens from time to time, babies adapt. But when this pattern becomes the norm, it has a fundamental effect on babies' developing brains. When their brains are bathed in stress hormones on a regular basis, they become more vulnerable to stress. Further, their bodies become hyper-responsive to stressful stimuli. That increases their vulnerability to depression not only in childhood, but throughout their lives.

By breastfeeding, and parenting in a responsive way, mothers are ensuring that their babies are not chronically stressed--and that shows up years later as decreased rates of depression and myriad other health problems.

Can a non-breastfeeding mother get the same effect? Yes, of course. But she will consciously need to be responsive to her baby's cues. From a practical standpoint, the beauty of breastfeeding is that this responsiveness is built into the system.

I think the takeaway message from this study is that responsive parenting does make a difference in how children fare throughout their lives. So it's something important for parents to consider next time someone advises them to let their babies cry it out.

What’s Stress Got to Do With It?: The Many Ways That Stress Impacts Our Health

Health care providers often tell me that they came to my lectures to learn about something for their patients, but they ended up finding something useful for themselves. They could be suffering from chronic pain, or heart disease, or metabolic syndrome. But they didn’t know that psychological stress was often a key part of why they were sick--and could even kill them.

In one of the first major studies in this field, researchers noted that people who were taking care of spouses with Alzheimer’s were dying at higher than rates than their non-caregiving peers. They were developing heart disease and cancer and other fatal diseases. I often think of Christopher Reeves' wife. Had caring for her severely disabled husband contributed to her own early death?

Researchers have also studied the link between depression and heart disease. Did you know that depression is a well-known risk factor for heart disease? Or that depression, hostility and other negative mental states increases your risk of developing diabetes?

Along these same lines, researchers have discovered that depression, stress or anxiety during pregnancy dramatically increases the risk of preterm birth. We are now beginning to understand why that would be so.

Sleep problems are another fascinating area of study. A lot of people know that sleep problems increase this risk of heart disease and diabetes. But what you might not realize is why they do.

The answer to these questions has to do with how humans respond to stress. And that is the focus of our installment. Stay tuned!