参考答案：D

解析：[分析] 推断题型。 见文章前两句：With the sudden onset of severe psychotic symptoms，the individual is said to be experiencing acute schizophrenia(精神分裂症)．“Psychotic”means out of touch with reality，or unable to separate real from unreal experiences．一个人如突发严重的精神病则患有急性精神分裂症，而患有精神病则意味着与现实脱节或无法区分真实和虚幻的体验。由此可推论出选项D．cannot distinguish real from unreal正确。