The main presenting features of mood disorders in children are: feelings of inferiority, coyness, excessive shyness, social withdrawal, anxiety, tendency to cry, excessive interpersonal sensitivity, depression, and persistent sadness. Most childhood mood disorders are exaggerations of normal developmental tendencies and are not absolutely abnormal in nature. The causes of mood disorders in children and adolescents generally arise because of being under persistent mental stress. Parental discord in the family, separation, death of a loved one, disputes among family members, and inappropriate educational methods such as frequent scolding, intimidation, threats, or other stressful events can have varying degrees of impact on children’s emotions. In older children, the proportion of influence caused by social environmental factors increases, such as excessive academic burden, interpersonal conflicts, and psychosomatic changes brought about by growth and development. Genetic factors, personality traits, and somatic states also play an important role in emotional responses. It has been suggested that the core symptoms of all childhood mood disorders are anxiety and fear. In the process of self-development, when a dangerous situation arises (i.e., threatened by a traumatic situation) it is necessary to resort to the production of anxiety as a forewarning of danger. Throughout the developmental process, the dangerous situations that a person encounters in childhood are, in order: “loss of the object” or “loss of the object called love”, i.e. fear of losing the mother; “loss of the love of the object “, i.e. the fear of losing the mother’s love; in the Oedipus period the child is in a conflict between love and hate for the parents; guilt, i.e. denial, revenge and punishment by the superego’s conscience. Some emotional reactions of children in everyday situations such as pain, grief, sorrow, anguish, annoyance, etc. are mostly normal. They may become normal after a few days. However, there are times when emotions are different and may last for weeks or more, and do not improve even after the environment improves, and may affect their learning, life, and interpersonal interactions. It must be taken seriously. Common clinical manifestations of mood disorders in children include separation anxiety disorder, phobic disorder, social sensitivity disorder, childhood obsessive-compulsive disorder, childhood dysthymia, and childhood depression. Because the cause of mood disorders in children lies in the different intensity of mental tension stimuli inside and outside the family. Therefore, the treatment focuses mainly on harmonizing the child’s environment through the relationship. Psychological intervention with parents and other concerned persons is as important as psychotherapy with the child. Appropriate medication is given to reduce anxiety or depressive symptoms when necessary.