The prevalence of affective disorders in children varies widely due to the different samples from which the investigators are drawn, the sample size, the age of the individuals, and the diagnostic criteria. So what are the differential diagnoses of association and affective disorders in children? 1.Simple grief reaction The loss of a favorite person or object in children can have extremely serious consequences for the child or adolescent, causing depression, loss of appetite, weight loss and insomnia. However, there is generally no feeling of worthlessness of life and no psychomotor retardation. There is no self-blame or guilt, no loss of pleasure, and not recurrent episodes. This reaction can occur immediately, usually not more than 3 months, sad reaction if long-term not eliminated can develop into depression. 2, affective syndrome due to organic disease Certain organic diseases, such as tumor, epilepsy, hepatomegaly, etc. can appear depressed mood, or obvious manic state should be distinguished from affective disorder, affective disorder due to organic disease is secondary, no psychomotor excitement or block, no low self-evaluation or exaggerated self-evaluation. A detailed history and neurological examination, EEG, CT and laboratory tests can help to differentiate. 3, schizophrenia children with affective disorders Especially juvenile mania appear psychotic symptoms, such as hallucinations, delusions, etc., easily misdiagnosed as schizophrenia, but children with schizophrenia personality changes are more prominent, their affective disorders are secondary, hallucinations, delusions and other psychotic symptoms and affective disorders are not coordinated, and then combined with the history of slow onset and family history, it can be distinguished from it. 4, anxiety disorders anxiety and depression often coexist Children with separation anxiety often appear secondary to depressive mood. However, depression in children with depression is severe and persistent, and depression is primary, with obvious suicidal ideation and psychomotor retardation. No pleasant sensation while anxious patients have severe and persistent tension and anxiety, as well as significant autonomic dysfunction. 5, conduct disorder children depression and mania can appear obvious behavior disorder, at this time should be distinguished from conduct disorder. Children’s conduct disorder is a repeated and persistent behavior disorder, the degree of which is much more serious than the general aggression, destructive behavior. The behavior disorder of manic-depressive children is relatively mild and occurs after manic or depressive mood, while children with conduct disorder may have depressive mood, but the behavior disorder occurs before the depressive symptoms. Generally through the medical history and examination can be identified. 6, attention deficit disorder Attention deficit children may appear excited, unable to sit still, increased activity, impulsive, irritable, and sometimes aggressive behavior, similar to mania. However, the behavioral problems of children with attention deficit disorder are chronic behavioral problems, no family history of affective disorders, ineffective treatment with lithium, etc. can help identify them.