Right now, it's not just the winter darkness that descends upon us. So does the darkness of depression. With winter comes an increase in the number of depressions. As the seasons change and hopefully soon bring brighter days, researchers are working to help persons suffering from depression out of the darkness by increasing our understanding of what happens in our brains when depression strikes.

Betina Elfving is driven by a scientific curiosity. Like a detective, she goes on a hunt to find the clues that the depression left behind in the patients' brains many years ago. At the same time, she is driven by a desire to make a difference for the many people who are affected by mental disorders, including depression, every year.

The desire to make a difference is a welcome effort. Depression is often referred to as a widespread disease. This is not without reason: Almost one in five Danes is affected by depression during their lifetime, and the consequences extend far beyond the person suffering from depressed. According to the Danish Health Authority, direct costs in connection with depression sum up to almost DKK 9 billion per year. Depression also has large personal consequences for family and friends, who may experience how the person suffering from depression disappears into her or his own darkness. To have a bad conscience about letting down the closest relationships can intensify the depression and give rise to questions about whether it is actually one's own fault and whether one should just "get it together". But when suffering from depression, you can't just pull yourself together. When the darkness of depression first envelops you, you often feel a paramount sadness. Guilt, low self-esteem and negative thoughts often accompany the darkness. The symptoms of depression are not only psychological, because many also experience that both sleeping habits, eating patterns and sex drive change significantly.

There is no need to feel guilty. Depression is a complex disorder that can affect anyone, and the causes are an interaction between many different factors. For example, interactions with other diseases, environmental factors such as social status and experiences in your childhood have an impact, but biology also plays a role in the form of, among other things, heredity and various biological processes.

Biology is the primary focus of Betina Elfving's detective work when she is looking at the small pieces of old brains from patients suffering from depression. Her main focus is microscopic markers called microRNA. Because of their microscopic size, microRNAs are very stable. Therefore, these tiny clues are still found in the very old bricks from the Danish Brain Collection. "Often I have to cut off a bit to remove the outermost layer of brain tissue, which has been damaged during the long storage. But already after a few slices, I can examine the microRNA in the tissue," explains Betina Elving. She wants to find out which microRNAs are found in the depressed brains and how much of each microRNA there is. In other words, she is looking for a biomarker. Like a clue in a detective case, a good biomarker can show whether a certain biological process is taking place in the body. For example, there are already several examples of microRNA which can be used to detect some forms of cancer.

"In the future, biomarkers can hopefully be used for both diagnosis and treatment of psychiatric patients. Of course, the biomarkers cannot stand alone. But they can be an additional tool that can ensure faster and more targeted help for the person suffering from depression," Betina Elfving says.

It is not simple to find a good biomarker for depression. According to Professor of psychiatry at the Capital Region of Denmark Michael Eriksen Benros, the perfect biomarker must be as precise as possible. At the same time, the costs to measure the biomarker must be justified in relation to how important it is for treatment "Probably a biomarker found in the brain will be best. But we must be able to measure it in the patients without major interventions," he explains.

Poul Videbech, who is also a Professor at Region Hovedstadens Psykiatri (the psychiatric unit of the Capital Region of Denmark), says that the greatest potential for biomarkers lies in being able to prescribe the best possible treatment for the individual patient: "Right now we have several different forms of treatment and types of medicine. But not all treatments work equally well for everyone. Therefore we have to proceed by the method of trial and error. It would be really important for the treatment of depression if we could use a biomarker to predict whether a treatment will work or whether it has, for example, unacceptable side effects.”

Today, there are three general forms of treatment for patients with depression: Psychotherapy, medication, and ECT. Psychotherapy, where the patient learns to tackle psychological and personal challenges through a series of conversations with a professional, is most often the preferred treatment for patients with mild or moderate depression. In some cases, psychotherapy is combined with antidepressant medication. ECT, short for electroconvulsive therapy, is the official term for what was previously known as electroshock. Contrary to what many people think, ECT is still a used, and often very effective, form of treatment in psychiatry. It is used in particular for patients with severe depression with, for example, suicidal plans, where the doctors assess that there are no other options for recovery.

Over many years, women have filled twice as much as men in the statistics of depression. However, according to project manager Michael Wichmann Pedersen from DepressionsForeningen (the Danish Depression Association), this does not necessarily mean that more women than men have depression. "This means that twice as many women are diagnosed with depression," he explains. He believes that there may be a large dark figure for men. Psychiatrist Michael Eriksen Benros fully supports this interpretation: "There may well be a large unreported figure of men, because they simply do not sufficiently consult a doctor - although of course there could potentially also be other contributing reasons."

Psychiatrist Poul Videbech does not necessarily think that there are a lot of men hiding in dark figures. "The causes of depression are incredibly complicated," he says. He points out that although women are certainly better at seeking a doctor, this alone cannot explain the big difference between men and women. Some of the difference can be explained, for example, by our own and others' expectations to ourselves, but the basic biology of the two sexes may also plays a role.

Although Betina Elfving is currently continouing her work with various biomarkers in the laboratory, the persons suffering from depression do not immediately benefit. "It can take a long time before you know whether your research will be a breakthrough or not. Even if it is a breakthrough, we are talking about a time perspective of many years before the research benefits the patients," says psychiatrist Poul Videbech. He emphasizes that Betina Elving's approach to biomarkers in the old brains is original and that her research is important because it will give us new knowledge no matter what.

Even if it turns out that one of the biomarkers can "only" be used to make a diagnosis, it may still prove to be important for those suffering from depression. "If you can detect depression with an objective biomarker using, for example, a scan or a blood test, there is not much to discuss. Then you are sick," says psychiatrist Michael Eriksen Benros, thus suggesting that an objective test might help to reduce the taboo associated with depression.

This resonates with project manager Michael Wichmann Pedersen from the DepressionsForeningen: "We often see that there is less taboo about something physical. It's easier to talk about. Therefore, one can well assume that it could help decrease the taboo associated with depression if you have a precise biomarker to make the diagnosis.” Fortunately, the staff DepressionsForeningen believe that there is a development in society which makes it easier to talk about psychiatric disorders. Admittedly, depression still lags behind in relation to, for example, talking about seeing a psychologist or suffering from stress. But we are heading in the right direction. Towards a society where we can talk openly about depressions, while we are waiting for a more patient-specific and targeted treatment.