Several unanswered questions
Commenting in the release, Eric Ruhe, MD, PhD, Radboud University Medical Center, Nijmegen, the Netherlands, said this was a “very interesting and difficult study to perform.”
However, Dr. Ruhe, who was not involved in the research, told this news organization that it is “very difficult to connect the lack of brain connectivity to the patient symptomatology because there is a huge gap between them.”
The problem is that, despite “lots of evidence” that they are effective, “we currently don’t know how antidepressant therapies work” in terms of their underlying mechanisms of action, he said.
“We think that these types of therapies all modulate the plasticity of the brain,” said Dr. Ruhe. “What this study showed is there are changes that you can detect even in 6 weeks,” although they may have been observed even sooner with a shorter follow-up.
He noted that big questions are whether the change is specific to the treatment given, and “can you modulate different brain network dysfunctions with different treatments?”
Moreover, he wondered if a brain scan could indicate which type of treatment should be used. “This is, of course, very new and very challenging, and we don’t know yet, but we should be pursuing this,” Dr. Ruhe said.
Another question is whether or not the brain connectivity changes shown in the study represent a persistent change – “and whether this is a persistent change that is associated with a consistent and persistent relief of depression.
“Again, this is something that needs to be followed up,” said Dr. Ruhe.
No funding was declared. The study authors and Dr. Ruhe report no relevant financial relationships.
A version of this article first appeared on Medscape.com.