Playing.
D001010:Anxiety, Separation; D002648:Child; D002652:Child Behavior; D002657:Child Development; D002673:Child, Hospitalized; D003142:Communication; D005201:Fantasy; D005639:Frustration; D006801:Humans; D007266:Inhibition, Psychological; D007398:Interpersonal Relations; D010287:Parent-Child Relations; D010817:Physician-Patient Relations; D010988:Play and Playthings; D011340:Problem Solving; D011613:Psychotherapy; D012043:Regression, Psychology; D012951:Socialization; D013315:Stress, Psychological