In almost every initial consultation, patients and families ask us, “Is my condition serious?” or “Is my child’s condition serious?” Even at later follow-up visits, they repeat this question. In fact, this is a question that is difficult to answer accurately or completely, and there is not a very strict or precise or even “one-size-fits-all” criterion for the severity of a patient’s condition. Here, I will try to give a more comprehensive answer to this question. From a psychiatrist’s point of view, I think there are at least four evaluation criteria for determining the severity of mental illness, namely, the degree of pain suffered by the patient himself, the degree of impairment of the patient’s social functioning, the degree of pain and anguish caused to other people, and whether or not there is any impairment of the ability to test reality. Although the severity of mental disorders is mainly reflected in the degree of subjective suffering and the degree of impairment of social functioning according to the current almost globally accepted diagnostic criteria for mental disorders such as the Diagnostic and Statistical Manual of Mental Disorders (DSM) system in the United States, in some cases the patients with mental disorders also cause great suffering to others due to their illnesses, the loss of self-awareness and impairment of reality-testing ability also indirectly reflect the complexity and severity of their complexity and severity of the disease, and even play a decisive role in the prognosis of the disease. Therefore, in this paper, we will also discuss the criteria for determining these two aspects. The subjective degree of suffering of mental patients varies according to their age and the illness they suffer from. Compared with adults, the subjective degree of distress of younger patients is often not entirely consistent with the severity of their illness. For example, due to the fact that some people have experienced fewer painful events in life and have fewer standards of reference for the experience of pain, they may either have a tendency to downplay the “young people do not know the taste of sadness” and lack strong experience of pain, or they may have an excessively strong experience of pain due to the fact that they have seen too many strange things. The latter is more pampered in the usual way. The latter is more common in adolescents who have been pampered and spoiled and have had a smooth upbringing in the past. Children and adolescents with disorders such as social phobia or obsessive-compulsive disorder (OCD), which do not significantly conflict with their environment, are also less subjectively distressed than adults. Of course, the degree of subjective suffering is strong enough to make the patient to take suicidal behavior that is fatal or to harm his own body, naturally, the disease is serious enough to show that the phenomenon is worthy of great attention and need to take immediate treatment. Second, the severity of social function impairment The degree of social function impairment involves not only the patient’s age and disease at the time of illness, but also their pre-morbid level of functioning, as well as the gap between their level of functioning and that of the group, especially the peer group. Since patients of different ages have different major psychological developmental tasks, the impairment of social functioning should be determined by the extent to which the disease affects the patients’ major psychological developmental tasks, rather than by a “one-size-fits-all” or uniformly single standardized measure. For example, if the primary psychological developmental task of adolescence is “social exploration and companionship”, i.e., the establishment and maintenance of close relationships or friendships with peers that ensure the individual’s increased social adaptability and synchronized growth in a group, the consequences of impairment of this developmental task can be quite serious, even if the current impairment of functioning does not appear to be significant. Similarly, psychiatric disorders in childhood and adolescence that lead directly to disengagement from the peer group, such as social phobia or “school phobia,” can result in a long-lasting and persistent return to the peer group, even if the impairment is not significant in other areas of functioning, such as the ability to learn, to care for oneself, to read, to use computers and the Internet, or even to survive on one’s own. The long duration of this impairment can result in significant and lasting difficulties in returning to their peer group. This is because, after being separated from their peers, whose psychological development is “rapidly changing” or “impressive”, these patients will inevitably form a huge gap with their peers’ level of psychological development, and it will be difficult for them to catch up in a relatively short period of time, and they may even be subjected to the same level of psychological development as their peers. It is difficult to catch up in a short period of time, and may even be coldly rejected, ostracized or mocked by peers because of this gap, which puts patients with poor psychological ability in a more difficult situation. In addition, some mental disorders that start in childhood, adolescence and young adulthood are also a criterion of seriousness because of the patients’ lack of self-awareness and impairment of functioning in anticipation of serious consequences, even though the severity of their symptoms is not serious. For example, the Internet-dependent behaviors that are common among these children, adolescents and young adults, where addiction to the Internet prevents them from maintaining normal social activities with their peers, playing sports, and completing their education, can lead to both a lag in psychological development behind their peers and the loss of critical graduation and employment opportunities. When they are not able to integrate into the social environment that normal people should be integrated into, they are very prone to stress reactions or other mental disorders. These types of mental disorders, which are determined by the patients’ own age, their lack of self-awareness and their inability to foresee the serious consequences due to their short-sightedness, are often underestimated by psychiatrists, as well as by the patients and their parents, who also underestimate the seriousness of the consequences and accordingly the severity of the mental disorders. I always say that it is reasonable to judge the severity of a patient’s illness by predicting the long-term outcome of mental disorders that are “pies” in the present but “traps” in the future. The damage caused by a patient’s mental illness to his or her social functioning can be reflected both vertically by the degree of change in the level of social functioning and horizontally by comparison with the average level of the majority of his or her peer group living in the same social environment. The former is based on the state of good adaptive ability before the disease as the normal standard, such as before the disease in the school and the workplace have good adaptive and social skills, after the disease both adaptive ability to decline, and social skills of the decline, such as reluctance to go out to participate in any face-to-face interpersonal communication, are suggestive of the more serious condition. Of course, if the patient’s social adaptation and social skills were already deficient to a certain extent before the disease, and there is a significant decline in functional status after the disease, it suggests that the severity of the disease is more serious, and also suggests that the long-term prognosis of the patient is not good. The latter is reflected in the gap in growth synchronization with the group, if the patient’s adaptive and social skills have become more and more obvious with the peer group, also suggests the severity of the disease. If this state lasts long enough, the patient’s social function may even be irreparably damaged, losing the opportunity to return to the peer group. Third, the severity of pain and trouble brought to others by the patient’s illness Generally speaking, the degree of pain and trouble brought to others is essentially related to the degree of subjective pain and the degree of impairment of social functioning, but very often it is also related to the views and attitudes of others towards the patient’s illness. The greater the degree of concern of others, the greater the degree of pain and anguish that the patient’s illness manifests to others. Regardless of the type of mental disorder, the patient’s illness will certainly cause corresponding pain and anguish to his or her blood relatives. On the one hand, the patient’s relatives will suffer because of the patient’s abnormal behavior and abnormal emotional reaction, for example, the relatives of the depressed patient witness the patient’s depressed and pessimistic state, and have a strong painful experience. On the other hand, the patient’s abnormal speech and behavior will also bring pain, trouble and embarrassment to the patient’s relatives, and even panic when the patient’s abnormal speech and behavior lead to legal disputes, so that the relatives are often in a state of anxiety and panic that they do not know what kind of abnormal behavior the patient will appear in the next moment, and how they should deal with it. Therefore, the intense pain caused by the patient to the relatives is also one of the criteria for evaluating the severity of mental illness. Patients with mental disorders may also disrupt and threaten the living patterns and personal safety of other people in their living environment, and may disturb and disrupt the rules of society and social order because of their pathological mental activities. For example, a patient with psychotic symptoms of delusion of victimization will be implicated and suspected of someone in the real-life environment, believing that the person is the “mastermind” or “accomplice” of the persecution activities carried out against him or her, and the patient often feels that he or she can “bear it no more” when he or she is in a situation of “unbearable”. “When the patient feels that he or she can no longer tolerate the persecution, he or she will attack the person verbally or physically, causing others to be hurt for no reason. Others may be affected by delusions of grandeur, convinced that they are being persecuted and that they need to shock society into paying attention to their suffering through behavior that is shocking to society. Such a patient may achieve this by creating violent incidents of great impact, often resulting in tragic injuries to innocent people in society. It is also a sign of a more serious mental illness if a mentally disturbed patient not only experiences intense subjective pain, impaired social functioning, and causes great pain and distress to his relatives, but also inflicts harm and malignant stimulation on others in the social environment. Loss of self-awareness and impairment of reality-testing ability The sign of impairment of reality-testing ability is the loss of self-awareness and psychotic symptoms such as hallucinations and delusions. One of the essential differences between patients with mental disorders and patients with other physical diseases is the cognition and attitude towards the disease state. Patients with mental disorders often lack an objective, rational and realistic understanding of their illness or abnormal state, and lack the corresponding motivation to seek treatment. The typical attitude and behavior of “avoiding medical treatment” can be seen in many patients with mental disorders. This phenomenon is known as “loss of self-knowledge” in the field of psychiatry, and such cognition and attitude often leads to the progressive aggravation of the patient’s condition and the loss of early and optimal treatment, resulting in treatment difficulties and poor prognosis. The absence of self-awareness is also one of the phenomena of higher severity of the condition. The most important sign of impaired reality-testing ability is the appearance of significant psychotic symptoms such as hallucinations and delusions. In such cases, the patient lacks the ability to recognize illusory perceptual information and seriously distorted thought content, and is convinced that such information is completely deviated from reality, and is governed and influenced by it to do behaviors that are difficult to understand by ordinary people, or even to endanger the patient’s own life and the safety of other people’s lives and property. For patients with indications of a more serious degree of illness, it makes sense to act as early and as quickly as possible so that the patient can be seen and treated in a timely and effective manner.