Just not the parts that control imagination!
Depression is one of the most common mental health conditions, affecting 1 in 10 people in the UK each year. And yet medications are basic and their mechanisms not fully understood or effective. Most people know the signs and symptoms of depression, but what about the science that leads to these feelings?
Depression is linked to changes in the brain’s chemistry
Essentially, depression results from alterations in the brain that disable regulation of emotion. To treat depression, we need to improve the brain’s ability to regulate mood.
Neurotransmitters are chemicals that pass messages between nerve cells - increasing the availability of certain neurotransmitters in the brain increases function and combats depression.
For example, the neurotransmitter serotonin influences multiple areas of the brain (including areas associated with mood, appetite, sleep, and memory/learning). Reduced levels of serotonin have been linked to depression, and lower levels of a by-product of serotonin has also been associated with an increased risk of suicide. The majority of antidepressants increase serotonin levels to treat depression.
But how serotonin controls emotion is still not well understood and needs to be investigated if we want to develop more effective treatments.
For example, the neurotransmitter serotonin influences multiple areas of the brain (including areas associated with mood, appetite, sleep, and memory/learning). Reduced levels of serotonin have been linked to depression, and lower levels of a by-product of serotonin has also been associated with an increased risk of suicide. The majority of antidepressants increase serotonin levels to treat depression.
But how serotonin controls emotion is still not well understood and needs to be investigated if we want to develop more effective treatments.
Depression is related to nerve cell death
The hippocampus is a region of the brain associated with learning and memory. The size of the hippocampus is significantly smaller in people with recurrent depression. This is due to increased cell death, which results in less brain connections and therefore reduced brain activity.
Patients experiencing their first episode of depression have a normal sized hippocampus, and the size decreases with sustained depression. Therefore it’s essential that depression can be identified early and treated effectively to prevent such damage.
It’s likely that the cell death arises due to depression, and research has shown that stress negatively impacts the nerve cells in the hippocampus. But there are undoubtedly other mechanism(s) behind the cell death that we need to understand to tackle depression.
Patients experiencing their first episode of depression have a normal sized hippocampus, and the size decreases with sustained depression. Therefore it’s essential that depression can be identified early and treated effectively to prevent such damage.
It’s likely that the cell death arises due to depression, and research has shown that stress negatively impacts the nerve cells in the hippocampus. But there are undoubtedly other mechanism(s) behind the cell death that we need to understand to tackle depression.
Our genetics play a role in depression
The risk of developing depression is 40-70% related to genetic factors, and indeed one study highlights how networks of hundreds of genes across the brain are altered in depression, demonstrating the complex nature of depression.
For example, the shorter your serotonin transporter gene is, the more likely you are to develop depression in response to stress. This isn’t something you can control, you’re born with it.
However, recent research also demonstrates that certain genes make you more sensitive to your environment, and depending on that environment, more likely to have depression or be very positive. Therefore depression is a consequence of complex interactions between our biological make-up and the conditions surrounding us.
For example, the shorter your serotonin transporter gene is, the more likely you are to develop depression in response to stress. This isn’t something you can control, you’re born with it.
However, recent research also demonstrates that certain genes make you more sensitive to your environment, and depending on that environment, more likely to have depression or be very positive. Therefore depression is a consequence of complex interactions between our biological make-up and the conditions surrounding us.
What else is there to learn?
So much! Current research only scratches the surface of depression and its influencing biological and environmental factors. There is a lot more to understand.
MQ is currently funding two projects that hope to better understand the role of serotonin in depression: 1) investigating whether genetic regulation by serotonin is different in people with depression and 2) to map the activity of serotonin in the brain.
But there is so much more to investigate, and that will only be possible through increased funding into mental health. I have chosen to support MQ because of their commitment to increasing scientific research into mental health, but also for their research strategy – MQ are involving the public in their decision process; for example surveying more than 3000 people to find out their priorities for research into depression. Therefore we, the public, are having a say in what we want to see researched, something that should happen more in science.
Results of the MQ 'Depression: Asking the Right Questions' project with James Lind Alliance Priority Setting Partnership
This is a very brief overview of the science of depression, below are two links you might find useful if you want to know more:
http://www.medicaldaily.com/science-depression-biology-behind-darker-mind-299078
http://www.health.harvard.edu/mind-and-mood/what-causes-depression
http://www.medicaldaily.com/science-depression-biology-behind-darker-mind-299078
http://www.health.harvard.edu/mind-and-mood/what-causes-depression