Psychological disorder refers to an abnormal state in which individuals can't effectively adapt to environmental requirements according to social norms or appropriate ways, thus showing psychological activities.

In clinic, the concept of "psychopathology" is often adopted, and a wide range of psychological abnormalities or behavioral abnormalities are collectively referred to as "psychological disorders" or abnormal behaviors. Of course, the word "behavior" here is broad, referring to all observable actions or activities, including almost all aspects of human function. The reason why it uses the word "observable" is to make the study of psychology or behavior an objective scientific study.

Generally speaking, "psychological disorder" has a relatively general definition, which refers to the inability to act in a way that society thinks appropriate, so that the consequences of its actions are not suitable for itself or society. This "inability" may be the result of organic damage or functional damage, or both.

Psychological disorder: On the basis of brain physiological and biochemical dysfunction, and the imbalance between subject and objective display, people produce distorted responses to objective reality, which affects people's behavior and impairs people's ability to adapt to social life, understand and transform the world. The manifestations of psychological disorders are quite complicated, from the cognitive process of psychological activities such as feeling, perception, attention, memory, representation, thinking and imagination to the emotional process, motor desire, will behavior, intellectual structure and personality characteristics. But the common psychological disorders are: there are illusions and hallucinations in the process of perception; There are amnesia in the process of memory, delusion and some language and logic obstacles in the process of thinking; The disorder of emotional process is mostly manifested as anxiety, depression, terror, etc., and the disorder of will behavior can be manifested as excitement, restlessness or rigidity, or weird behavior, etc. Mental disorders can be manifested as retardation and dementia; Personality disorder is mainly manifested in various forms of morbid personality.

Psychological abnormality is a distorted reflection of objective reality based on the dysfunction of brain physiology and biochemistry and the imbalance between man and objective reality.

The word psychological abnormality is a general term for many different kinds of psychological and behavioral disorders. Its manifestations can be serious or mild. People often use words such as psychosis, abnormal behavior and emotional disorder to describe and distinguish it in daily life, and even use unprofessional words such as "nervous breakdown" to describe the psychological disorder that suddenly occurs and impairs work ability. In particular, people often use the word "neuropathy" to refer to "psychosis" and "neurosis", which is very confusing and harmful. Therefore, the scientific classification of psychological abnormalities not only helps to deepen the understanding of psychological abnormalities and provide reference for diagnosis, treatment and clinical research, but also helps to eliminate people's vague or wrong understanding of psychological abnormalities and popularize mental health knowledge.

It can be seen that psychological abnormality includes psychological disorder, which is a kind of psychological abnormality;

Psychological abnormality also includes psychological disorder. "The word psychological abnormality is a general term for many different kinds of psychological and behavioral disorders". "Its performance can be serious or slight", and the psychological disorder is the most serious.

Mental illness refers to a phenomenon that a person deviates from the norms of social life in thinking, emotion and behavior due to mental tension and interference. The greater the psychological and behavioral deviation from the norms of social life, the more serious the mental illness will be.

It is very common, but there are differences in degree. Moreover, with the development of modern civilization, human beings are increasingly divorced from their natural attributes. Pollution, fast pace of life, nervousness, unprecedented information, complex social relations, changes in work and rest styles, differences in consumption orientation, unfair facts under the concept of fairness, and doting have gradually increased and worsened mental illness. There are many kinds of mental diseases with different manifestations, and there may be more that have not been noticed before or have been rationalized (not considered as mental diseases). With the changes of the times, there are also many newly discovered mental diseases.