Involvement of the central nervous system in systemic lupus erythematosus is frequent (50-66%). Its manifestations may be either neurological, psychiatric or both. The psychiatric syndrome may appear without physical symptoms, or may accompany severe systemic involvement. In either case psychiatric diagnosis is quite difficult and consequently treatment is often controversial. We review current knowledge and present the case of an 18-year-old male which illustrates the complexity of both diagnosis and treatment of the syndrome.