In 1988, for the first time in its thirty years history, the Collegium Interna tionale Neuropsychopharmacologicum (CINP) with one of its biannual congresses returned to the same city - to Munich. In Munich, 26 years ago (1962) the IIIrd CINP Congress had been held. A comparison of these two Munich CINP Congresses is evidence for the fruitful growing and expansion of research in basic and clinical neuropsychopharmacology. In 1988, more than 3000 people attended the XVIth CINP Congress. And it was necessary to have - besides poster presentations - up to fourteen parallel sessions. By decision of the Programme Committee (A. Coppen, E. Costa, H. Hippius, J. Mendlewicz, G. Racagni and I. Yamashita) 65 symposia to special topics had been accepted and were held during one week. These symposia were the core of the congress. Special scientific highlights of the congress were the four plenary sessions. There, lectures were presented by two Nobel Prize Laureates- G. Edelman and M. Eigen -and six other outstanding scientists (B. Sakmann and the CINP members W. E. Bunney, A. Carlsson, P. Janssen, M. Schou, G. Sedvall). With the aim to inform about the results of the XVIth CINP Congress as many scientists as possible, the CINP Executive Committee and the Pro gramme Committee published in a separate volume the abstracts of all symposium-presentations, all platform- and poster-presentations ("Psycho pharmacology" - Supplement to Volume 96 - Springer International 1988).