KKFC Psychiatric evaluation (Child Psychiatrist will be masked to study status). Child Psychiatrist evaluation will determine whether medication is appropriate for the child and whether the child/family environment is stable and safe. If the child is deemed appropriate for psychotropic medications, other than stimulants, the child will not be eligible for the study (due to the possible changes in one of the outcome measures, heart rate variability, that will likely result from use of psychotropic medications that can not be stopped 24 hours prior to study evaluation). [Children on stimulant medication will be asked to stop medication one day prior to study evaluation and of the day of evaluation.]