In a recent review3 G. F. Solomon and I found the mean incidence of psychosis in systemic lupus erythematosus (S.L.E.) to be 22%. We also found that in several reports, patients had had a psychosis for months or years prior to the onset of the systemic features of lupus erythematosus. In the case we reported the patient had had a psychosis continuously for 16 years before S.L.E. was diagnosed. We felt that in some cases the evidence suggested that psychosis might be the first, and often even sole, manifestation of S.L.E. We wondered about the incidence of S.L.E. in a chronically psychotic population and decided to screen such a population for the presence of the so-called lupus factor in their serum by means of the nucleoprotein latex agglutination test.In contrast to S.L.E., rheumatoid arthritis (R.A.) has been thought to be very rarely associated with psychosis.
W. J. FESSEL. Disturbed Serum Proteins in Chronic PsychosisSerological, Medical, and Psychiatric Correlations. Arch Gen Psychiatry. 1961;4(2):154–159. doi:10.1001/archpsyc.1961.01710080050008