Abstract: ADHD is a common behavioral disorder characterized by the symptoms of inattention , hyperactivity and behavior impulse. While ADHD is a group of diseases which often occur in combination with one or more mental or non-mental disorders. Previous studies on comorbidities of ADHD mostly confine to symptoms of one or several comorbities, so we don’t have a system understanding of this issue. Comorbidities of ADHD can be divided into three parts according to the temporal order of occurrence. That’s pre-comorbidity ,simultaneous comorbidity and post-comorbidity. Pre-comorbidities present before the appearance of core symptoms of ADHD. For example, disturbance of sleep and autism spectrum disorders (ASD) may precede first clinically relevant ADHD symptoms. Simultaneous comorbidities coincide with the time when ADHD symptoms reach a clinically significant level. Researchers find that some people with ADHD are diagnosed with non-organic enuresis and encopresis when ADHD symptoms reach a clinically significant level. What’s more, develop-mental dyslexia which is characterized by difficulties with reading comprehension, reading decoding, reading fluency and spelling, may manifest as simultaneous comorbidity with ADHD. Post-comorbidity is an important part of these comorbidities. These disorders in people with ADHD often occur several years after the appearance of core symptoms. For example, some people with ADHD have related symptoms of depression later on in the course of ADHD. As depression, researchers find that people with ADHD may also show symptom of anxiety disorders, OCD, CD, ODD and substance use disorder later on in the course of ADHD. On the basis of this classification, researchers will have a relatively systematic understanding of this issue. They will also have a more specific aim in the future studies. In this way , future studies will provide researchers with more effective material for the diagnosis and treatment of ADHD. To understand the development of comorbidity and do better in the diagnosis and treatment of ADHD, longitudinal study in patients with ADHD should be strengthened in the future.

Key words: ADHD, comorbidity , time sequence

摘要： 多动症是一种常见的行为障碍，它以注意力不集中、多动、行为冲动为主要特征。同时多动症是一组异质性疾病，常与一种或几种精神或非精神障碍相伴发生。以往关于多动症合并症状的研究，大都局限在一个或几个合并症状上，缺乏关于其合并症状的系统认识。基于以往研究，文章以多动症合并症状发生的时间顺序为线索，将其分为前期、同期、后期合并症，并逐一详细介绍。未来应该加强关于多动症患者的纵向研究，以了解症状的发展状况，更好的诊断和治疗多动症。

关键词: 多动症, 共病, 时间顺序