Intellectual Disability (Intellectual Developmental Disorder) (ID/IDD) is both a psychiatric disorder and a risk factor for co-occurring psychiatric disorders in children and adolescents. DSM-5 introduced important changes in the conceptualization and diagnosis of ID/IDD, and current research studies clarify assessment and treatment of co-occurring psychiatric disorders in this population. Optimal assessment and treatment of psychiatric illness in children and adolescents with ID/IDD includes modifications in diagnostic and treatment techniques, appreciation of variations in the clinical presentation of psychiatric disorders, an understanding of the spectrum of etiologies of behavioral disturbance, and knowledge of psychosocial and medical interventions.

智力障碍（智力发育障碍）（ID / IDD）既是精神疾病，也是儿童和青少年并发精神疾病的危险因素。DSM-5在ID / IDD的概念化和诊断中引入了重要的变化，目前的研究澄清了该人群中同时发生的精神疾病的评估和治疗。对患有ID / IDD的儿童和青少年进行的精神疾病的最佳评估和治疗包括对诊断和治疗技术的修改，对精神障碍临床表现变化的认识，对行为障碍病因谱的了解以及对心理社会和精神疾病的了解医疗干预。