Severe depression acts out in a different way in the brains of youth as compared to adults, a research has found. In young people with severe depression, disruptions in the way regions of their brain communicate with each other are not the same as observed in adults.
This has been highlighted in a research published on Tuesday in Nature Mental Health which can help identify potential targets for brain stimulation therapies.
The study, led by the University of Melbourne, with third-year PhD student Nga (Connie) Yan Tseanaly as the first author, analysed the brain scans of 810 young people aged 12-25, of which 440 had major depressive disorder (MDD), while 370 were healthy individuals used for comparison.
The researchers found that in youth with MDD, some densely connected regions of the brain (known as hubs) showed stronger connectivity while weaker connectivity was witnessed in others when compared with individuals without depression.
The connectivity was found to be stronger in someone’s internalised thoughts and ruminations, Prof Andrew Zalesky, the supervising researcher, said. “We see that in youth with depression, the default mode is more strongly connected, it’s more activated, which suggests that there is a greater focus on self-thought and self-reflection,” Zalesky said.
The study could also predict the severity of a person’s depressive symptoms. Data from previous independent studies from six sites in Australia, China, the United Kingdom and the United States was also used for the study.
Zalesky called it “the largest sample size of youth with depression and healthy comparison”.
He added that when first-line treatments, such as antidepressants do not work in treating depression, brain stimulation therapies can be targeted to repair specific brain circuits.
However, the treatment has mostly been used only for adults because researchers know which circuits are disrupted.
Currently, targets developed to treat adult depression with transcranial magnetic stimulation (TMS) are used as a “best-guess approach” for youths, the research found.
Australia’s medicines regulator recommends TMS only for adults, but Zalesky believes it can be used to treat youth at the clinician’s discretion.
“The assumption is that the same circuits would be affected in youth with depression, and our work shows that that’s not necessarily the case.”
He added that more study is needed to test the efficacy and safety of brain stimulation therapies in youth “but this is a necessary first step towards providing targets”.