During clinical treatment, many patients and family members are concerned about whether mental illnesses will be passed on to the next generation and often consult their physicians about the genetic aspects of mental illness. In fact, the role of genetic factors has been found in many studies on the pathogenesis of primary mental illnesses, but in clinical work, many patients with mental illnesses do not have similar patients in their families. Patients and family members are left wondering whether mental illness is hereditary or not. In daily life, many people will find that a mother and daughter or father and son have similar physical appearance, the so-called “dragon gives birth to a dragon, phoenix gives birth to a phoenix”, this is the role of genetic inheritance, the same genes make many physical characteristics are inherited, and at the same time, human character or personality traits also have a genetic tendency, many children have similar personality traits with their parents. Many children have similar personality traits to their parents, and some ways of thinking and behaving are also inherited, so there are many families with personality disorders. Among psychiatric disorders, those that are more closely related to heredity are schizophrenia, bipolar disorder (manic and depressive episodes), depression, etc. Most psychiatric disorders are the result of a combination of endogenous (genetic and other factors) and exogenous (environmental, psychosocial stress, etc.) factors, but the difference is that the proportion of internal and external factors is different. In contrast, psychosocial factors play a larger role in the development of depression, and in the case of endogenous depression (marked biological changes and recurrent episodes), the proportion of endogenous factors is greater. Therefore, schizophrenia, bipolar disorder, and endogenous depression have a greater genetic predisposition. However, genetic studies of these disorders have shown that they are mostly polygenic, that is, they are not genetically determined by a single gene, so they are not 100% hereditary, but are influenced by the environment against a genetic background. Therefore, many people with these diseases marry and have children who do not develop the disease. However, if both spouses are affected (which is less likely), it is not advisable to have children, as this condition can greatly increase the rate of disease in children. In summary, although schizophrenia, bipolar disorder, endogenous depression and other disorders have a clear genetic tendency, not all of them are inherited, they are the result of a combination of genetic and environmental factors, and inheritance is a complex role of multiple genes, so we should not blindly fear that mental illnesses will be inherited to our children, and we should consult our doctors for the specifics!