Researchers Identify 6 Subtypes of Depression
About 30% of people diagnosed with major depressive disorder don’t respond to treatment. But thanks to new research identifying six clinically distinct biotypes in depression, scientists may be able to help identify potential treatment responses.
The Research Results
A team of Stanford Medicine researchers used fMRI to measure the brain activity of 801 participants who had been previously diagnosed with depression or anxiety. They looked at brain activity at rest (task-free), as well as while the person was engaged in tasks in order to analyze emotional and cognitive functioning.
To test optimal treatments for each biotype, the researchers had 250 participants (randomly assigned) to receive behavioral talk therapy or one of three commonly used antidepressants (escitalopram, sertraline, venlafaxine XR).
Common brand-names for these antidepressants are:
• Escitalopram (e.g., Lexapro)
• Sertraline (e.g., Zoloft)
• Venlafaxine (e.g., Effexor extended release)
By looking at the connections between brain regions, the scientists were able to identify six distinct activity patterns. The team found that, compared to other subtypes:
• Participants with one subtype (characterized by overactivity in cognitive regions of the brain) responded the best to venlafaxine.
• Participants with a different subtype (characterized by a higher level of activity in three brain regions associated with problem-solving and depression) responded best to behavioral talk therapy.
• Participants with a different subtype (characterized by lower activity levels in the brain circuit that controls attention) were LESS likely to see improvement with talk therapy. (It’s worth noting that people with this subset of depression may be helped by taking an antidepressant to increase activity in the brain before engaging in talk therapy.)
“The biggest takeaway is that we can identify specific types of major depression that have a root cause in specific brain regions and networks,” explained senior author Dr. Leanne Williams, who lost her partner to depression in 2015. “This discovery can be transformative. It is a path for moving beyond diagnosis based only on observed symptoms, which is a one-size-fits all approach that doesn’t tell us which treatment will work best for each person. [It] opens the door for precision medicine in mental health.”
Implications for treating depression
While it’s hopeful to think that depression screenings could include a brain scan in the future to help identify each patient’s subtype and therefore, the best treatment, there are limitations in terms of cost and resources. Clinicians who work in a private practice or smaller setting likely won’t have access to fMRI scans.
However, the research is a big step in the right direction for those suffering from treatment-resistant depression. Considering that approximately two-thirds of people with depression receive treatments that fail to reverse symptoms back to healthy levels, it can take months (or years) for someone to get matched with the right medication and dosage through trial and error.
“The goal of our work is figuring out how we can get it right the first time,” said Williams. “It’s very frustrating to be in the field of depression and not have a better alternative to this one-size-fits-all approach.”
The study was published in the June 17, 2024 edition of the journal Nature Medicine.
MBJ
Wendy Burt-Thomas writes about the brain, mental health and parenting.
Check out the original research:
