Question: how does your brain react to feelings of depression and what causes these feelings?

Jen Todd Jones answered on 15 Mar 2013:

Hi experimentalist

I’m glad you asked here, I couldn’t answer fast enough in the chat! Our brain is a very complex organ full of chemicals, called neurotransmitters, that help us think, and move, and live. Some of these chemicals, in particular serotonin, are related to depression and feeling down. Depression usually means an unusually low mood that stays around for a long time and can’t be shifted. There is some question as to whether this is because of the chemical in the brain being unbalanced, or the depression makes the chemical become unbalanced – this is an important principle in science, in which direction does the influence go? What affects what? So when asking how the brain reacts to feeling of depression, perhaps you should say depression is a reaction to the brain!

The serotonin, or actually a lack of it, is what we have thought causes the feelings of depression and sadness. Serotonin is sometimes called the happy drug of the brain, and is what helps us feel happy and pleasant – it can be increased during exercise, or eating chocolate and even singing! With less of it we feel sad and tired, although recent research actually suggests its not serotonin but its effect on another chemical, called brain derived neurotrophic factor, that creates new brain cells in important brain areas that make us feel better.

Depression is closely linked to anxiety, too, which is exactly what it sounds like, feeling anxious all of the time but sometimes without having a specific reason. This is actually a very useful feeling for the brain, we feel anxious when we’re in danger and this helps our brain understand that we should get away – or even helps us concentrate, for example panicking just before a test! But sometimes it gets out of hand and makes us feel bad, and then we can suffer from depression too.

These things are more common today than they have been before but are still pretty rare, everybody is sad or anxious from time to time, like I said it’s a normal part of having a brain! Someone should be worried if they have been feeling very sad or anxious constantly for longer than one or two months.

Jen