In the morning it is still dark when the alarm goes off, during the day you only see cold people with jackets, hats and umbrellas and on the way home from work it dawns long ago: autumn is here. And so for many people at the same time the season of bad mood, fatigue and the long-term desire to be for the next few weeks with the explanation "I have the autumn blues!" to set up on the sofa.

Some contemporaries may see this kind of bad mood as one of those temporary, rather harmless, malaysia that does not have much to do with depression. Keywords: holiday blues, weekend blues, christmas blues. For others, the term "autumn blues" is nothing but a charming attempt to give everyday grumpiness a prettier expression. But the psychiatrist Dietmar Winkler, professor at the University of Vienna, contradicts: "The autumn blues is by no means a myth." In fact, medicine also knows the "seasonally dependent depression", abbreviated SAD, meaning English for "sad". The extreme form of the autumn blues, so to speak.

The American psychiatrist Norman Rosenthal discovered her in the 1980s after one of his patients from the wintry Jamaican vacation had reported surprising things. After only a few days in the Caribbean sun, her depression had disappeared, she felt as good as usual only in summer. Through a newspaper ad, Rosenthal found nearly thirty thirty men and women who experienced similar things each winter. As soon as the days got shorter and the weather got worse, they felt limp and dejected. Everything seemed gray and hopeless. They wanted only to sleep, could concentrate badly and always felt a strong appetite for sweets. With the first warm spring days, all this subsided ( General Psychiatry : Rosenthal, 1984).

Not rain or cold, but lack of light is the problem

Only one out of every 50 people suffers from such severe winter depressions. This was the result of a survey of almost 1,000 Austrians by the research group of psychiatrist Dietmar Winkler. But what we call autumn blues - a lighter form of it - is quite common: it affects at least one in six ( European Psychiatry : Pjrek et al., 2016).

It is not the cold and rainy weather that put people to death. The problem is the lack of light in the shorter autumn days. For our internal clock, which signals to the body when day and when is night, the diminishing brightness brings with it a great change. When the photoreceptors on the retina in the eye register daylight, the brain sends commands to the pineal gland, which produces the sleep hormone melatonin at night: stop, it's day, no more melatonin! But if it is still dark in autumn and winter when we are awake, the pineal gland continues to produce melatonin. We may get worse out of bed in the morning, tired, lacking energy and drive. In patients with winter depression, this effect is very clearly measurable: Melatonin can be detected in their blood well into the day ( JAMA Psychiatry : Wehr et al., 2001).

Adaptation to the cold months was vital for our ancestors. Dieter Kunz, physician

Another possible explanation for bad moods in autumn and winter provides the messenger substance budget of the brain. Sunlight, for example, measurably boosts the production of the serotonin known as the Happiness Hormone - whereas in the darker months it releases significantly less ( The Lancet : Lambert et al., 2002). Also in the metabolism of the messengers dopamine, important for motivation and drive, and norepinephrine, which controls alertness and attention, scientists have discovered seasonal variations ( Brain Imaging in Behavioral Neuroscience : Praschak-Rieder et al., 2012).

However, this physiologically controlled energy low in human history was not always as annoying and pointless as it may seem to us today. "Adaptation to the cold months was vital for our ancestors," says Dieter Kunz from the Charité Berlin. Retreating to the cave once it was cold and dark outside helped save the body's energy to keep warm. A kind of "hibernation light".