Non-drug Study to Assess the Suitability of Assessment Scales in Japanese Individuals With Down Syndrome Aged 6-30

Inclusion Criteria: * Subjects may have standard trisomy 21, Robertsonian translocation, isochromosome21,Down syndrome with reciprocal translocation or mosaicism. * Availability of parent or other reliable caregiver who agrees to accompany the subject to clinic visits, provide information about the subject's behavior and symptoms. * Down Syndrome subjects meeting clinical diagnostic criteria for generalized anxiety disorders, major depressive disorders, autism spectrum disorder, attention deficit and hyperactivity disorder, can participate to the study provided they are on stable medication for at least 8 weeks prior to screening. Exclusion Criteria: Individuals who may not be able to comply with the protocol or perform the outcome measures due to significant hearing or visual impairment or other issues judged relevant by the investigators.