You can name any numbers, and they will be true, because according to modern huge classifiers, every emotion can be interpreted as a mental illness. Until the middle of the 20th century, people were simply different, and then they wanted to get approval for their normality. Only now there is no concept of normality, but different features of behavior began to be considered mentally and diseases. In psychiatry, there are a lot of diseases that are defined subjectively and do not have a criterion, that is, if you wish, you can declare a person sick and imprison him. The film "Psychiatry is an industry of death" tells that in the USA people who have insured their health for large sums are simply forcibly taken to a psychiatric hospital in order to be treated for their own money. Just think that every model of behavior is like and any action can be a justified response to the threat. Anger is a normal reaction to latent hostility (remember Kirkorov's clashes with journalists). For every action you can find an example of a reason that justifies it. Another example: 25% is a quarter. If in a family of a husband, wife and two children, three people are idle, and the wife does all the organizational and homework, naturally she will be annoyed by the idleness of the others, and she will yell at everyone. But the reason is not in her behavior, but in her husband's unwillingness to help in terms of the distribution of responsibilities. Let many of us are crazy, but the treatment does not consist in isolation, but in communication and help from others.
It depends on what you mean by "mentally ill"
As mentioned earlier, all without exception periodically suffer from a number of processes, for example, depression, neurosis and neurasthenia, etc.
Therefore, the incidence rate quoted by you is extremely doubtful.
And nevertheless, there are conditions that come and go with the course of conditions provoking them, also those that a person can cope with on their own.
But there is also another contingent of people who underestimate their condition. this is no longer the norm, but not yet a disease.
A person cannot and cannot cope with this on their own, therefore, one way or another, soon it develops into a pathology. But he cannot or cannot consult a specialist wants, for various reasons, for example, an elementary squeeze or underestimation of his condition.
I answered a similar question in this thread: thequestion.ru
I think it's relevant here.
I wonder where you got the mysterious figure of 25%.
First, it can be argued more or less calmly that every resident of a big city has or periodically experiences certain mental deviations. Just like to say that every resident of a big city has certain health problems or periodically experiences diseases: caries, flat feet, scoliosis, flu, tonsillitis, cardiovascular diseases from a sedentary lifestyle, poor nutrition and the use of any harmful and etc. Do you have at least one acquaintance who does not get sick from this and has never been sick? Well, the problems from the so-called. minor psychiatry: depression, mild neuroses, mild phobias, mild panic disorder. Shaking before exams, any addictive behavior (starting with smoking), obsessive behavior - from chordering to orthorexia, any persistent inability to establish satisfying relationships with others, to stable orderly activities, any long-term sustained (or regularly occurring) feeling of unhappiness - that's all. indicates certain mental problems. And I don’t know a single person who hasn’t experienced any of this at one stage or another in life.
Secondly, the concept of a mental norm is generally quite difficult to define, there are a lot of approaches to it, one another more beautiful, and from each of them someone falls out of ordinary people whom we are used to seeing on the street, in the social circle and in the mirror. Moreover, it is also changing: the mental norm now and the mental norm a hundred years ago are two different norms. And this is due to the fact that one of the most important criteria of the norm is adaptability to society, and society is changing in our time very quickly and very strongly. Today, in fact, it can be assumed that for different generations, the criteria for the norm should be slightly different. But this is a very fragile and very unexplored area.
Thirdly, the more or less stable percentage of people who have experienced at least one psychotic attack during their lifetime, for developed countries - 1% (as far as I know).
I think 100% of the patients are sick, they / we just don't know about it yet, and if they do, they don't tell anyone. For example, I guarantee that I am sick. Just shhhh, let it be our little secret.
And with obvious deviations from "generally accepted norms" 25% is quite a good number ... why not? I think there are just as many others in whom these deviations are not so obvious, or with a sufficiently long period so as not to be noticed.
By our nature, and to some extent, we are all mentally ill and even crazy, but we ourselves do not admit it and will never admit it. This does not manifest itself strongly and everyone has it in different ways, but most do not even suspect it. I bet that many people noticed a state of imbalance or too strong influence from an incomprehensible side. They are not aware of their unbridled actions .. sometimes even in the heat of the moment, but they always refer to any reasons, but not a mental disorder. If everything went well, people would not take a sedative.