Childhood Depression and the Amygdala

This will be the last post on the brain for now.  I’ve written about several parts of the brain that affect depression or are affected by depression.  Now I’d like to talk about the amygdala.  I’m writing in very basic terms so don’t be scared away by the subject.

The amygdala has been called the center of emotions.  It has also been called the fear center.  One of the jobs of the amygdala is to form and retain emotional memories and memories related to emotional events.  Another job of the amygdala is to detect threats and control our fear response that gets us ready for fight or flight.  Fight or flight is the fear response.  When we feel in danger, do we run or do we fight?    

Our muscles tighten our blood pressure increases, our stomachs feel like they get tied into knots, our respiration increases, we sweat more and we may get chill bumps on our skins.  This is the fear response but these are also symptoms of a panic attack. 

In threatening situations, we need this fear response to protect ourselves but for some children, they feel threatened in relatively normal situations like when they talk to someone new or when they’re in a crowd of people or when they are away from the people and places that make them feel safe.   

Research has shown that the brains of depressed and anxious children are very similar to the brains of depressed and anxious adults.  Their amygdala can become overly active when seeing, feeling and experiencing negative emotions and under active when seeing, feeling and experiencing positive emotions.

When depressed children experience negative emotions, their overactive amygdala may cause them to feel those emotions too strongly and too deeply.  When they experience positive emotions, their underactive amygdala may cause them to feel those emotions less acutely than the average person. 

Other research has shown that children with larger than normal amygdala can be more anxious and may be at a greater risk of developing an anxiety disorder or depression when they grow up.  Not all children with larger than normal amygdala have or will have problems but many do or will.  Other studies have shown children with depression may have smaller than normal amygdala. 

A larger than normal amygdala is seen in childhood anxiety but a smaller than normal amygdala is seen in childhood depression.  It’s kind of confusing.  I’ve always had trouble with both.  I think it’s more about the amount of activity in the amygdala; too much activity can cause the amygdala to be hypersensitive and the child to feel negative emotions stronger, less activity can make it less sensitive making it more difficult to feel positive emotions 

Research has shown that stress, poverty, trauma and other negative events in childhood can affect the development of the amygdala causing it to be over active sometimes and under active at other times.  

When the amygdala processes information it sends a signal to the hypothalamus causing the hypothalamus to release CRH hormones.  The HPA axis is activated and cortisol is released.  Too much activity in the amygdala causes too much activity in the HPA axis causing too much cortisol, which can kill some neurons and can keep new neurons from forming in certain areas of the brain.    

I’ve said it before, the brains of depressed and anxious children are different.  These differences can cause children to feel emotional pain more intensely.  These children are not just being difficult.  They truly hurt and need the sympathy and empathy that anyone with an illness deserves.

I realize all this brain stuff can be complicated but I hope I’ve helped some people understand childhood depression a little better.  Thanks so much.  My next posts will be about how parenting types can affect childhood depression.