Research strategies in 'slow' infections in psychiatry

The research processes in the elucidation of the causes of general paresis, the first slow infection in psychiatry, and of Kuru, the first slow virus infection in man, were considered. The errors and difficulties encountered may contribute to the formulation of research strategies for contemporary work on possible persistent infections with unknown viruses as a cause of psychiatric disorders. Clinical obsservation, bold hypotheses and methodological advances appear more valuable than diagnostic categorization in etiological research into psychiatric disorders. The low heuristic value of diagnosis is due to the lack of specificity of psychiatric symptoms and syndromes, especially in low grade organic disturbances.