- Adults with major depression who experienced childhood trauma have volume differences in certain brain regions, a recent study shows.
- Previous research has shown that people who experienced childhood trauma are vulnerable to depression later in life.
- Brain scans could help researchers identify different types of major depression and find the most effective treatments for specific types.
Events during childhood may continue to affect our emotions as adults.
Now for the first time, we can see the signs in brain scans, according to researchers at the University of Alberta in Canada, presenting a 2021 study.
The theory is that childhood trauma interferes with the development of the brain, creating tiny weaknesses. As an adult, those weaknesses make some people less able to cope with stress. They then fall into depression.
To be clear: None of this means you (or someone you love) is doomed. It is a reason to be forgiving of yourself if you don't respond to stress as quickly or easily as you'd like. And the new brain scan research may help lead to better targeting of treatments.
Scans Reveal Differences in Certain Brain Regions
Improvement in brain scan technology has made it possible to see more clearly into the human brain, focusing on smaller sub-structures within big ones. In the past, scientists could only look closely at those sub-structures in animals.
The Alberta team matched 35 adults with major depression to people without the illness of the same age, sex and education. The volunteers were sets of 12 men and 23 premenopausal women. All the volunteers underwent magnetic resonance imaging (MRI) brain scans and filled out a standard Childhood Trauma Questionnaire.
The brain weaknesses showed up in the hippocampus and amygdala, two areas involved in emotion and memory that grow and change in childhood. Those areas are thought to be vulnerable to traumatic events.
Looking within those areas, the researchers saw that in volunteers who had depression and also reported childhood trauma, the anterior hippocampus (part of the hippocampus that plays a role in making decisions during conflicts) and right amygdala (linked to fear and sadness) were smaller. There also seemed to be changes in an area called the basolateral amygdala, involved in responding to danger.
Fewer brain cells may mean that those areas are less effective at processing conflict, fear and sadness. What might that feel like? Let's say you are afraid of losing your job. You know you need to go look for a different job and put aside some money to tide you over. But instead, you feel paralyzed and start drinking alcohol in the evening. You're angry at yourself for reacting that way. You end up depressed—feeling like nothing you can do will make a difference or just too tired to make an extra phone call. You're literally lacking brain power (which has nothing to do with intelligence).
What Is Childhood Trauma?
It’s important to realize that childhood trauma is common. By the age of 16, more than two-thirds of children experience at least one traumatic event, which might be psychological, physical, or sexual abuse; violence at home, in school or in the community; national disasters, sex-trafficking, sudden or violent loss of a loved one, assault, refugee or war experiences, serious accidents or life-threatening illness.
“Children may feel terror, helplessness, or fear, as well as physiological reactions such as heart pounding, vomiting, or loss of bowel or bladder control. Children who experience an inability to protect themselves or who lacked protection from others to avoid the consequences of the traumatic experience may also feel overwhelmed by the intensity of physical and emotional responses,” the National Child Traumatic Stress Network, created by Congress in 2000, explains.
Brain Scans Could Help with Selecting the Best Treatment
Right now, the diagnosis of major depression covers patients with very different symptoms—and possibly distinct illnesses. Brain scans are already helping researchers come up with more specific categories.
This is a big group among depressed patients. In one study, 62.5 percent of people with major depression reported more than two traumatic events compared with 28.4 percent of the controls. Patients who had experienced abuse between ages 4 and 7 years had the worst response to treatment with Zoloft (sertraline).
Psychiatrists now rely on intuition and trial and error to match treatments to patients—information from brain scans could speed up and fine-tune the process.
In theory, the research described here could lead to a day when you might be told that you get impulsive when you’re anxious because childhood trauma slowed the growth of your basolateral amygdala, and that a specific drug helps boost its functioning.
The information about brain changes also could help speed basic drug research. Psychedelic drugs, for example, trigger nerve regrowth in specific areas—suggesting how they may help people with depression.
The bottom line: Childhood trauma is a health vulnerability.
A version of this post also appears at Your Care Everywhere.