他的行为看起来像是精神失常。

His behavior seemed like lunacy.

他因为精神失常被送进了医院。

He was sent to the hospital because of lunacy.

他们认为他的计划简直是精神失常。

They thought his plan was sheer lunacy.

在那种情况下，精神失常是可以理解的。

In that situation, lunacy is understandable.

他被诊断为精神失常，需要接受治疗。

He was diagnosed with lunacy and needed treatment.

在突发的精神失常中试图从四楼的窗户跳出去。

Tried to jump out of the fortieth-floor window in a moment of utter lunacy .

恐怖的经历使他精神失常.

The terrible experience unhinged his mind.

他经这一打击精神失常了。

The shock unhinged his mind.

她在儿子死后精神失常了。

She went (ran) mad after the death of her son.

她精神失常了。

Her mind was unhinged .