mental disorder / psychiatric condition：
心理障碍，心理疾病

ADHD -- Attention Deficit Hyperactivity Disorder
注意缺陷多动障碍
It's characterized by not being able to pay attention, fidgeting a lot, always moving, not being able to focus.
它的特征是注意力难以集中，常常坐立不安动来动去的。
fidget 坐立不安，烦躁
Sit still and stop fidgeting!
坐好，不要动来晃去的！

ASD -- Autism spectrum disorder
自闭症，孤独症
autism 自我中心主义 （aut-自己，ism-主义）
It refers to a broad range of conditions characterized by challenges with social skills, repetitive behaviors, speech and nonverbal communication.
它指的是一种影响广泛的疾病，特征是社交障碍，重复性行为和语言，不爱开口说话。
We know that there is not one autism but many subtypes. Most influenced by a combination of genetic and environmental factors.
自闭症有很多不同的类型。大部分都是由于遗传学因素和环境学因素的共同影响。

Bipolar disorder
双相情感障碍，躁郁症
Another common mental illness is called Bipolar disorder, also known as manic-depressive disorder. A mental disorder that causes periods of depression and periods of mania or hypomania.
另外一种疾病叫做双相情感障碍，又叫做躁郁症。会导致持续性的或抑郁或狂躁的心情。

MPD -- Multiple Personality Disorder
人格分裂，多重人格障碍
multiple 多种多样的，数量多的