Human genetic diversity and neuropsychiatric disorders (K.K. Kidd). Section I. Methods and Models. Paralogous genes and nervous systems (L-G. Lundin, D. Larhammar). The candidate gene approach in psychiatric disorders: the example of tyrosine hydroxylase (J. Mallet, R. Meloni). Molecular analysis of genomes and genes (U. Landegren). The molecular basis for acute intermittent prophyria, an inherited disease associated with neurological and psychiatric disturbances (P.M. Shoolingin-Jordan, S.P. Wood). Section II. Candidate Genes in Psychiatric Disorders. Genetics of the 5-HT transporter: allelic variation in functional expression affects anxiety- and depression-related personality traits and suceptibility to affective disorders (P.K. Lesch, A. Heils, D. Bengel). Genetic variation in human dopamine receptors (M.M. Nothen, S. Cichon, P. Propping). Section III. Psychiatric Diseases and Linkage Studies. Bipolar disorder: molecular linkage studies (W.H. Berrettini). Genomic screening in manic-depressive disorder (G.R. Verheyen, C. Van Broeckhoven). Genomic trinucleotide screening in neuropsychiatric disorders (M. Schalling, K. Lindblad, C.E. Burgess, C. Zander, P-O. Nylander, C. Engstrom, R. Adolfsson). Unstable DNA in psychiatric disorders (J.B. Vincent, A. Petronis, J.L. Kennedy). The case for an X-Y homologous locus in the evolution of language and the origins of psychosis (T.J. Crow). Current status of the genetics of narcolepsy (C.L. Barr, C.M. Shapiro). Section IV. Dynamic Expansion Related to Psychiatric Disorders. Genetic anticipation and brain genes (M.G. McInnis). The fragile X syndrome (P.J. Willems). Section V. Late Incoming News. The gene map of psychiatric disorder (J. Wahlstrom). Polyglutamine expansions and neurodegenerative diseases (F. Sandou, D. Devys, Y. Trottier, G. Imbert, M-E. Stoeckel, A. Brice, J-L. Mandel). Section VI. Clock Genes. A molecular mechanism for the control of circadian behavioral rhythms in drosophila (M.W. Young). Biological rhythms and psychiatric disease: focus on melatonin-related genes (D.C. Klein, S.L. Coon, K. Mazuruk, M. Bernard, P.H. Rosenboom, I.R. Rodriquez). Section VII. Future Research. Genomic screening in schizophrenia (H.W. Moises). Future directions in genetics and psychiatric disorders (P.M. Conneally).