1. Servizi Psichiatrici, U.S.S.L., 51 Via S. Sebastiano, 26100 Cremona, Italy
2. Institute of Psychiatric Demography, Aarhus Psychiatric Hospital, 8240 Risskov, Denmar
3. Institute of Psychiatric Demography, Aarhus Psychiatric Hospital, 8240 Risskov, Denmark