When a person loses contact with reality and experiences irrational ideas and disordered perceptions, they are experiencing:

psychosis.

Explanation:

Psychosis is a mental condition in which mind begins to loose contact with what is real. During psychotic episodes the person faces difficulty in comprehending and differentiating between what is real and what is not. He begins to experience distorted perceptions, hallucinations, etc.

The probable cause of such conditions may arise due to substance abuse, extreme stress, trauma, etc. The symptoms of psychosis includes drop in grades or professional performance, lack in concentration, lack in self-care,  etc.

Therefore, the correct answer is psychosis.

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