The topic says that life in cities is more impersonal, which makes us assume that there will be more unhappiness and, therefore, more depression in them than in the countryside. If we look at some Spanish statistics on the diagnosis of disorders such as schizophrenia, this could be the case.
But we already discussed it a few months ago: according to a new and important study from the University of Chicago, and for counterintuitive As it may seem, the larger the city has, the lower rates of depression are found (referring of course to the rates due to this factor exclusively, since there are other dimensions that greatly influence its appearance, such as marital status, situation labor and gender of the subject).
It also happens that this work took into consideration a criterion somewhat different from that of many other studies that have investigated the same: to measure the prevalence of depression they were not based solely on population surveys from the country’s Mental Health Services, but added a mathematical model … applied to Twitter. Digging through the tweet history of individuals with geolocation activated and responding via semantic trees and machine learning to the nine DSM-IV diagnostic criteria for depression. Their technique, they say, has an accuracy rate only slightly less reliable than surveys done by experts.
The mathematical growth that explains the greater serendipity of cities (and its effects)
Still, their results, they say, are stable and consistent across all sources: the prevalence of depression systematically decreases with the size of the city. Specific, every time the size of a population doubled, there was a 12% lower rate of depression among its members.
And this is where the magic appears, or the call urban scale theory, a concept from a few years ago in the social sciences, also based on mathematical models, behind which it is believed that a multitude of factors can be explained about the modes of organization of life: a well-known study is that people walk faster in the cities. For a region of 10,000 inhabitants, the average citizen tends to walk at 3.5 km / h, while in cities of a million they normally go about 5.8 km / h. This means that we can say that a city with twice as many inhabitants as another has a pace of life that is approximately 12% faster.
According to Andrew Stier, a PhD candidate in integrative neuroscience at the University of Chicago and author of the study we mentioned at the beginning, this pattern of 12% by population doubling is found in many other studies that take into account the size of populations to explain the rates. invention, the variety of jobs, the number of social interactions, the plurality of catering options and the degree of crime.
In all the cited examples, twice the size, that approximate response of an extra 12% appears. The same rule appears if we evaluate the capacity and speed of spread of the covid. According to a 2015 University of Colorado study, this pattern of urban scale has been experienced in societies around the world dating back to 1150 BC.
Loneliness is criminal. Urban interactions protect us from it
Why the big city helps fight depression is simple: by increased social interaction. Cities have infrastructure networks (streets, railway lines, etc.) which, curiously, tend to “vary in a predictable way with the size of the population of each city” and which tend towards the densest environments. Higher density is a natural promoter of more human interactions.
There is the possibility, as has been seen in some other studies, that in some types of rather small populations, these lower degrees of interactions are compensated because those that are produced are of higher quality (your family, your friends), but Chicagoans find that large cities generally compensate for the lack of quality in their interactions with a more of them, something that would compensate the average citizen even if he is an immigrant and has no family in New York or Berlin. There is also a trend that suggests that there is a way to improve the quality of the same in large urban centers: building more passage and recreation areas. More parks.
Finally, we have other statistics in Spain that would help to support this theory of 12%, or at least that of the lesser potentiation of depression by large cities: our statistics on suicide, a phenomenon highly related to mental disorders. According to a recent study by the Ministry of Health, the so-called Empty Spain concentrates 25% of suicides while due to its population percentage it should only register 20%. The consumption of psychotropic drugs is much higher in populations of up to 10,000 inhabitants, and not only by their elderly people, but there is also greater consumption among their mature people.
Depopulation, lack of job options … And also a gender gap that is already occurring: the smaller the municipality, the fewer women of reproductive age there are, since they emigrate to the big cities in search of opportunities, and greater loneliness and isolation, greater ballots to suffer.
Thus, the suicide rate in Asturias or Galicia is 13 and 12 per 100,000 inhabitants when in Madrid or Catalonia it is 5 and 6 respectively. The paradox is that according to INE surveys a few years ago, the person with the least chance of receiving a diagnosis of mental health problems in our country was the male from a rural environment. Another fact to take into account: if in Spain there are already problems to receive mental health care, the possibilities are even more reduced in rural areas.