1. K.-P. Lesch, A. Heils, S. Petri, Department of Psychiatry, University of Würzburg, Füchsleinstrasse 15, 97080 Würzburg, Germany.
2. D. Bengel, B. D. Greenberg, J. Benjamin, D. L. Murphy, Laboratory of Clinical Science, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA.
3. S. Z. Sabol and D. H. Hamer, Laboratory of Biochemistry, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
4. C. R. Müller, Institute of Human Genetics, University of Würzburg, Am Hubland, 97074 Würzburg, Germany.