the class of disorders known as anxiety disorders,

精神紊乱可以分为焦虑症
the class of disorders known as dissociative disorders,

解离症
and the class of disorders known as personality disorders.

以及人格障碍
And these are the main psychological problems.

以上是主要的心理问题
When a psychologist or psychiatrist does his or her work,

心理学家或精神病医师在工作的时候
they're predominantly focused on somebody who has one of these problems.

他们把注意力放在有心理问题的人群
Some of them are rare

其中一些问题并不常见
but some of them such as anxiety disorders

但其中像焦虑症
and the mood disorders are very common.

和情绪紊乱都非常普遍
About 1% of the world's population suffers from schizophrenia

世界上百分之一的人患有精神分裂症
and this is the most common reason for being in a mental hospital.

精神病院里大多数是这种患者
And the reason for that is because of its severity,

因为精神分裂症是种非常严重的疾病