A team at the Karolinska Institutet found that some patients who recovered by accessing depression treatment showed an increased level of serotonin transporters
This year, a new blood test was created to assess future potential of depression. And in January, a US-based team figured out how to use neuromodulation to ‘cure’ severe depression, within the space of 30 minutes.
The interconnected function of blood, brain and depression hold the answers for healthcare professionals who want to help their depressed patients.
In the pursuit for knowledge about how depression works in the brain, scientists have always found low levels of serotonin to be a catalyst for the mental illness. In fact, many antidepressants function by blocking a protein that would siphon serotonin away from nerve cells.
Now, a team at the Karolinska Institutet have studied the brains of 17 ‘cured’ individuals, who report that their depression has faded after significant cognitive behavioural therapy.
What did they find in the successfully treated brain?
That serotonin levels are not a fixed certainty.
A person who is living with low serotonin, doesn’t have to remain that way.
Last author Johan Lundberg, researcher at the Department of Clinical Neuroscience, Karolinska Institutet, explained: “Our results suggest that changes to the serotonin system are part of the biology of depression and that this change is related to the episode rather than a static feature – a state rather than a trait.
“The finding raises many questions about the function of the serotonin system in depression and opens up for lines of research that could challenge the prevailing concept of serotonin and depression.”
10% higher after three months
They found that levels of 5-HTT were 10% higher after three months of treatment, when 13 of the 17 patients reported a significant improvement in their symptoms.
The team measured levels of 5-HTT in 17 individuals with depression before and after a course of internet-based cognitive behavioural therapy. The measurements were achieved with positron emission tomography (PET), a brain imaging technique in which scientists can gauge levels of different substances in the brain using radioactive tracers.
Interesting, but much more research needed
Jonas Svensson, postdoc researcher in Dr Lundberg’s group, said: “One possible interpretation is that the serotonin system doesn’t cause depression but is part of the brain’s defence mechanism for protecting itself against depression. One might hypothesize, for example, that the level of 5-HTT drops when an individual is subjected to stress, such as during a depressive state, and that the level rises or normalises when this stress goes away.
“It’s important to point out, however, that even if these ideas are raised by our study, its design doesn’t allow us to draw any conclusions about why levels of 5-HTT change.”