Some argued that existing diagnoses such as "delusional insanity" or "adolescent insanity" were better or more clearly defined.

Katherine herself suffered mood swings, depression and several mental breakdowns, culminating, in her later years, in what her doctors called "systemized delusional insanity."

Even if he could persuade the Captain that there was some truth in what he was saying, that he was not, in fact, suffering from some form of delusional insanity, the 'answer would be the same: "Nobody is going to murder you on this ship.

He spent the last 15 years of his life in mental hospitals, first for a short period at Barnwood House in Gloucester, and then at the City of London Mental Hospital, Dartford, where he was diagnosed as suffering from "delusional insanity (systematised)".