Safety and Efficacy of NDTx-03 in Children and Adolescents With ASD or SCD

Inclusion Criteria: 1. Children and adolescents aged 10 to 18 years. 2. Diagnosed with Autism Spectrum Disorder (ASD) or Social Communication Disorder (SCD) by the clinical judgment of a psychiatrist according to DSM-5 diagnostic criteria, based on the Autism Diagnostic Interview-Revised (ADI-R), Korean Wechsler Intelligence Scale for Children, Fifth Edition (K-WISC-V), and clinical assessment. Previously performed ADI-R and Wechsler intelligence scale results may be used; for Wechsler intelligence scales, any test type or version may be used, including K-WISC-V, WPPSI, or WAIS. 3. Full-Scale Intelligence Quotient (FSIQ) \>= 70 or General Ability Index (GAI) \>= 70 based on a Korean Wechsler intelligence scale (regardless of type or version, including K-WISC-V, WPPSI, or WAIS). Previously performed results may be used. 4. Able to use NDTx-03 installed on a smartphone, either independently or with assistance from a parent/legal guardian. 5. Able to comply with the recommended investigational device application schedule (5 times per week, 8 weeks, 40 sessions). 6. Agree not to use any medical device other than the investigational device during the clinical trial. 7. Agree that there will be no changes during the study in the regimen of medications that may significantly affect sociality. Medications being taken at screening may be continued, but total daily dose, active ingredient, and other regimen details must remain unchanged until the end-of-study visit. 8. Agree not to participate in additional Applied Behavior Analysis (ABA) treatment/rehabilitation/education or sociality-related treatment/rehabilitation/education programs during the study. Programs being received at screening may be continued, but frequency and treatment method must remain unchanged until the end-of-study visit. 9. The participant and parent (or legal guardian) voluntarily decide to participate and provide written informed consent/assent using the participant information sheet and informed consent form. 10. Willing to comply with the clinical trial protocol. Exclusion Criteria: 1. Clinically significant behavioral problems, emotional regulation problems, psychotic symptoms, or risk of self-harm or harm to others at a level that may affect the treatment process. 2. Severe acute or chronic medical or psychiatric disease. 3. Serious trauma or surgery within 4 weeks before the screening date. 4. Other severe neurological disease or disability, such as brain lesion disorder or mental disorder/disability. 5. Currently participating in another clinical trial or participated in another clinical trial within 30 days before the screening date. 6. Less than 24 months have elapsed since the end date of application of the investigational medical device NDTx-01 (or Buddy In) as of the screening date. 7. Participation in a clinical trial of, or prior experience using, a digital therapeutic device or software-based intervention program that may affect efficacy assessments of this study, including cognitive function, attention, executive function, language, social development, social skills, behavior, or emotional regulation, within 12 months before the baseline visit. 8. Within 8 weeks before baseline, a change in the dosage or regimen of medications that may significantly affect sociality, or a change in participation in treatment/rehabilitation/education programs that may significantly affect sociality. 9. Any other case in which the investigator determines that participation is inappropriate for ethical reasons or because it may affect clinical trial results.