A subset of people with newly diagnosed depression respond less well to conventional medication. These can apparently be detected through a combination of behavioral testing and fMRI scans. Can the long and painful search for a suitable therapy be shortened in the future?
Antidepressants help many people with depression — but not all. For example, one in three people affected could belong to a newly discovered subgroup of people with depression for whom antidepressants are less effective and therefore may need other treatment options. Out of control, and easily distracted
This group of patients had difficulty planning ahead, exercising self-control, and suppressing inappropriate behavior on behavioral tests. Overall, their cognitive response was slowed. They also had trouble concentrating, even when distracted.
Cognitive changes were expressed as a decrease in activity in specific areas of the frontal lobe responsible for these tasks. A research team from Stanford University in California has classified specific depression as a "cognitive biotype" of depression. I would like individual therapy
Currently, people with depression are treated according to the principle of "trial and error": e.g., different antidepressants are tried one after the other. And since the effect is only visible after a few weeks, it can last.
"I regularly see patients suffering and becoming increasingly distressed and suicidal," says lead author Laura Hack from the Department of Psychiatry and Behavioral Sciences.
In the future, the researchers recommend individualized treatment of depression and the identification of subgroups such as the cognitive biotope. As they showed in their study, imaging methods can help to objectively measure brain activity. Three antidepressants, one goal
Researchers stumbled upon the subgroup when they randomly assigned about 1,000 severely depressed but untreated patients to one of three popular antidepressant drugs: escitalopram (Lexapro), sertraline (Zoloft), or venlafaxine XR (Effexort). They all work on the same principle: like most modern antidepressants, they affect the levels of serotonin in the brain.
At baseline and after 12 weeks of drug treatment, researchers used self-reports and psychiatric assessment to assess participants' depressive symptoms. In addition, information on sleep and nutrition as well as social and professional activities and quality of life was requested.
In addition, the subjects completed a series of cognitive tests at the beginning and end of the study, which measured, among other things, language memory, working memory, decision-making speed and concentration. Almost a third belongs to the "cognitive biotype"!
Twenty-seven percent of the participants were grouped into a cognitive biotype based on abnormal test results.
They responded worse to the three antidepressants they were given: 38.8 percent of them had their symptoms go away completely. In the group that did not belong to this subtype, it was 47.7 percent.
Concentration test in a brain scanner
In addition, 96 participants completed a special concentration test. At the same time, their brain activity was recorded using functional magnetic resonance imaging (fMRI). When the text "Go" appears in green, you should press the button as quickly as possible. If the word "NoGo" flashes red, they shouldn't do it.
Results: During the test, participants with the cognitive biotype had significantly lower neuronal activity than healthy controls in two brain regions: the dorsolateral prefrontal cortex and the dorsal anterior cingulate region.
Do other forms of therapy work better? Together, these two areas form controllers that, among other things, reduce unwanted or irrelevant thoughts that often plague people with depression. Procedures such as behavioral therapies, which address these problems from the start, or procedures that affect brain waves, such as transcranial magnetic stimulation (TMS), may help them better.
More individual treatments
“Depression manifests itself in different ways in different people. Finding commonalities - such as similar profiles of brain activity - helps specialists treat patients effectively by individualizing treatment," says Williams. MRI studies could contribute to this in the future.
The idea that depression is a single disease is outdated today. There aren't just emotional triggersser between people, but also differences in the physiological mechanisms. There can hardly be one active substance that helps everyone equally.