It would often have been better to continue treatment – the relapse rate for depression is high. Researchers have now shown a way of predicting the risk of relapse: it is therefore reflected in slow decisions. Patients with poor prognosis are therefore typically reluctant to make decisions about how much effort they want to spend on a reward. The relationship could lead to the development of a test procedure, the scientists say.
The quality of life drops to zero – depressed and without power, millions of people drag themselves through life. In some cases, only mood-enhancing medications help them. Studies have shown that this treatment should continue beyond symptom resolution to reduce the risk of relapse. However, it has so far been difficult to estimate when the medication can be stopped. “Around 30 percent of those affected relapse in the first six months after weaning. That is a very high percentage. So far, there is no established instrument that can be used to assess this risk, ”says Isabel Berwian from the University of Zurich.
As part of their study, she and her colleagues have now explored the extent to which a known tendency of depression patients can be used as an indication of the risk of relapse: people with depression are comparatively unwilling to try to get a reward. “Imagine that you are already in bed one evening. Then call friends and ask if you want to meet them for dinner in town. A healthy person will probably get up and go. A depressed person, on the other hand, tends to stay in bed even if he thinks he can feel joy in the action. The reason: the effort required for this seems too great, ”explains the scientist. This way of thinking is also reflected in the time it takes to make a decision for or against the action.
Is there a signature of the risk of relapse?
As part of the study, the scientists have now investigated to what extent this tendency is retained in patients during successful treatment and is linked to the later risk of relapse. The study involved 123 patients with recurrent or severe depressive illness. They were largely symptom-free through therapy, but continued to take antidepressants. However, they had already decided to stop taking the medication soon. 66 healthy controls were used as the control group.
As part of the study, all study participants completed a kind of test game to measure their decision-making time. You should sometimes violently press a button on the computer to win points. A successful balloon then inflated a virtual balloon until it finally burst. During the runs, there was always the choice between two alternative strategies that were associated with different successes but also efforts. The subjects had five seconds to choose between these alternatives. All participants completed 60 runs. Depression patients were also followed up for six months to determine if they had a relapse after stopping their medication.
Characteristically sluggish decisions
The evaluations of the tests initially showed a fundamental tendency: the decision-making time for the depression patients was longer than for the healthy comparison subjects: on average 1.77 compared to 1.61 seconds. In addition, depression patients mostly chose the least strenuous option. The most important result, however, was: Within the depressed patient group there was also a tendency to delay: People who relapsed after weaning took an average of 1.95 seconds to make their decision. According to the researchers, this reflects the extent to which depression is still asymptomatic in the background. Retrospectively, the researchers were able to correctly predict the risk of relapse with a ratio of two to one based on the decision time.
The study has thus made it clear that the decision-making time enables certain predictions to be made regarding the risk of relapse in the event of depression. Regarding the implementation of the method in a test, however, the researchers are cautious because, according to them, the practical suitability of the method appears to be unclear. “This indicator is promising, but we cannot yet claim that we have found the solution. Our results now also have to be confirmed again by more extensive studies, ”emphasizes Berwian. However, the results at least give hope: there seem to be opportunities to develop detection methods that could save patients from sinking again into despair.
Source: Swiss National Science Foundation, specialist article: Jama Psychiatry, doi: 10.1001 / jamapsychiatry.2019.4971