It is known that different mental symptoms may occur as early symptoms of acute viral meningoencephalitides. In herpes virus (HSV) infections of the central nervous system (CNS) the appearance of these symptoms is well documented (Juel-Jensen and MacCallum, 1972). The recurrence of psychotic symptoms in cases of recurrent HSV infections has also been described (Shearer and Finch, 1964; Drachman and Adams, 1962). In recent years serological observations of the prevalence of HSV antibodies in patients with psychiatric disorders have suggested a possible association of HSV infections with aggressive behaviour (Cleobury et al., 1971), as well as with psychotic depressions (Rimon and Halonen, 1969).