Scientists have measured brain activity in young people with and without depression and have found that the brains of depressed adolescents respond silently to distressing images. Previous research in depressed adults does not show this effect, implying that adolescent brain development may have specific vulnerabilities to disturbing information, and that perhaps the depressed adolescent’s brain shuns information that could ultimately make depression worse. Antidepressant treatment has been shown to restore this depressed brain activity to “healthy” levels. The work is presented at the ECNP conference in Lisbon.
Researchers at the University of Oxford compared the brain activity of 29 depressed adolescents to that of 16 healthy adolescents, aged 13 to 18. shown on an fMRI brain scan, (compared to non-depressed adolescents) in areas of the brain related to visual processing; the occipital pole (which processes visual information, found at the back of the brain) and the spindle-shaped gyrus (which is involved in processing faces, bodies, and colors, found near the brainstem and cerebellum). The images depicted scenarios such as someone crying, someone visibly injured, someone attacked.
As principal investigator, Dr Liliana Capitão said “The ability to regulate emotions is the key to social and emotional development in adolescents. What we saw in this study leads us to believe that depressed teens can avoid distressing information, which could potentially intensify their experience of depression. However, there are other possible interpretations and we need more work to confirm our ideas. For example, it might also reflect a form of ’emotional numbness’, where depressed teens shut down their emotions and don’t feel ‘involved’ in what is going on around them, or even reflect difficulty adopting the point. view of another person, as the images showed distressing images. situations that happened to others. This effect has not been found in previous work using the same distressing images in adults with depression, which could imply that there are potential vulnerabilities in the brains of depressed adolescents that are not found in the brains of depressed adolescents. depressed adults.”.
The 29 depressed adolescents received either the antidepressant fluoxetine or a placebo. After a single 10 mg dose (a normal starting dose) of fluoxetine, brain activity in depressed adolescents was found to increase to the same level as that of healthy adolescents (healthy adolescents did not receive or antidepressant or placebo for ethical reasons). Dr Capitão said:
“Fluoxetine increased neuronal activity after a single dose, showing effects on the brain within hours of administration. This could imply that this drug reduces the fact that the brain avoids feeling these distressing images very early in the treatment. This effect could help these depressed teens to tackle the problems that arise in everyday life, helping them to cope with the distressing experience. However, this is only a working hypothesis and needs to be confirmed on a larger scale. studies”.
She continued “We also want to refine our methods, for example by introducing eye-tracking, which would help us to understand if the participants were actively looking away from the distressing images.. It would also be important to improve the images presented, to better reflect the realities of negative situations experienced by adolescents and to make them more personal.
Commenting, Dr Henricus Ruhe, psychiatrist and senior researcher at Radboudumc, Nijmegen, Netherlands said:
“This is interesting proof of what could go wrong with young people who are depressed. First, it is unique to have recruited such a sample of young (depressed) young people and to involve them in this intensive fMRI research and to treat them with an antidepressant or a placebo. Understanding depression in this age group is extremely important, as most affective disorders begin in adolescence, but are often unrecognized. As symptomatology and new episodes seem to worsen over time in early adulthood, depression during adolescence may indicate a window of opportunity to intervene and change the course of the disease.
This study is important because it provides a clue as to how we measure adolescent brain function. Since adolescent brains are highly adaptive and continue to remodel, it might – compared to more mature adult brains – be more easily influenced by interventions such as cognitive training or cognitive therapy. I can imagine that researchers are thinking of this type of intervention to further support their theory and develop interventions to test in future studies ”.
Type of research: non-peer reviewed / experimental study / human subjects
Dr Ruhe was not involved in this work, this is an independent comment.
This work is presented at 34e ECNP Annual Conference, which takes place in Lisbon and online from October 2-5, see https://www.ecnp.eu/Congress2021/ECNPcongress. The European College of Neuropsychopharmacology is the main European organization working in the field of applied neurosciences.
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