We present a case of SLE psychosis with a characteristic symptom mainly concernd to time dysorientation.

A lady of 17 years old without any previous history is hospitalised to Jichi Medical University Hospital, because of covulsion. After this problem is disappeared, she became inactive, however, sometimes irritated without any specific reason. Brain imaging (MRI, CT) was normal, but EEG revealed slow waves as basal rhythme. Her physical state and labodatas fulfilled the criteria of SLE. She was treated with Steroid-pulse therapy (Methylpredonisolone 1.000 mg/day for 3 days), predonisolone 90mg/day (for two weeks) and finally betamethasone 8mg/day (for three weeks) which made her consciousness clear, and her behavior coherent.

During the periode of the steroid pulse therapy and the start of betamethasone, this patient repeated to say "the date is wrong". She believed that one year had already passed since her admission. She appeared to be perplexed continuously between the two different time standards (wrong standard of her own and the right one of common world). We could not correct her misunderstanding until her consciousness became clear.

This symptom of misunderstanding and perplexion derives from continuous dysorientation. We may call this "time gap experience". We could observe this type of dysorientation in a very slight consciousness clouding which continues stably during certain period. Therefore, “time gap experience” can be a key to find a psychosis based on somatic disease like SLE.