The law and child psychiatry differ on the acceptable age of children as court witnesses. Neither the law nor child psychiatry considers a child's competency or credibility strictly by age, but the law includes some age requirements for competency. The law is concerned with a child's intelligence and ability top relate facts, whereas the child psychiatrist considers a child's developmental stage and the stress level under which a child has been or may be operating. Studies are cited that confirm stress and trauma can adversely affect a child's memory. The use and effectiveness of hypnosis in children are questionable, a key reason being that children are by nature vulnerable to suggestion. Testimony by a psychiatrist for the child in certain cases is recommended, particularly for infant witnesses clearly below the minimum age of competency. A child psychiatrist could also testify in a case where loyalty conflicts or fear exists that might force a child to lie. In addition, a child psychiatrist witness could be used effectively as a spokesperson for a child in divorce custody and visitation disputes. Techniques for verifying the credibility of a child witness are discussed, as well as factors to consider in deciding when a child should testify in court. 29 references.