The thing about science is that on a daily basis, new information only shows us how much we still don’t know. It’s taken a long time for us to come to our present understanding of depression. And we still have a long way to go. While we may never fully understand how to cure depression 100% of the time, we continue to make progress in understanding what causes depression, and how best to treat it.
Is Depression a Chemical Imbalance?
Just a few short years ago, depression was considered to be caused by a chemical imbalance in the brain. The neurotransmitter serotonin, it was generally accepted, was to blame. This belief gained broader appeal when drug companies began to market their products as a solution to this imbalance. The only evidence seemed to be that for some people, it worked. Those who took drugs to boost the brain’s serotonin levels often did experience fewer symptoms. However, this may be for other reasons than we thought.
Depression Still A Physical Problem
So what causes this to happen in the first place? The shrinking of the hippocampus may be triggered by stress. Our bodies react to stress by releasing cortisol – the fight or flight hormone – to help us get through it. This is completely normal, but over the long term, it can have negative effects on the body. Interestingly, according to Scientific American, high cortisol levels in animals actually shrink the hippocampus. While it’s yet unproven that this is the case in humans, it makes a solid case for doing more research to find out.
Genetics a Factor in Depression
Genetics have also been proven to be a factor in depression. Serotonin is helped along by – you guessed it – a transport gene. Everyone receives one copy of the gene from each parent, and there are two kinds – short and long. After tracking 800+ young adults over 5 years, it was found that those with one short 5-HTT gene had a 33% higher chance of developing depression after stressful life events, while those with two short genes were even more at risk. However, those with two long genes did significantly better when exposed to similarly stressful events.
Genetics are likely responsible for the fact that depression and bipolar disorder both run in families. Having a bipolar identical twin gives you a 60-80% chance of developing bipolar disorder. While there is still much to learn, understanding the real cause of depression apparently means setting aside the preconceptions that have guided how it’s been treated for years.
What Does This Mean?
Depression is a complex problem that stems from multiple causes. Certainly, it is not a “weakness” or something one should just “get over.” And as studies of the depressed brain show, the effects of depression are compounded over time. In light of the latest research, it may be that future treatments will shift away from boosting serotonin to boosting the brain’s power to regenerate its own cells. While the knowledge itself is not a cure, it does show that our understanding of what causes depression continues to grow, providing answers that will guide the course of future treatments.