background 3-D representations of the frequency distribution of suicidal behaviour over time offer new opportunities to explore differences between populations of suicides, which may elicit different underlying dynamics. This approach has been applied when studying time patterns of suicide (attempts) in a large national population. method Data regarding all suicides (n = 14.702) and suicide attempts (n = 15.649) in Italy during the years 1997-2001, as registered by the Office of Judicial Statistics from the Istituto Nazionale di Statistica (istat) in Roma, have been plotted both as a function of clock time and as a function of the time of year.
results Maximum values of suicides are found in the morning hours throughout the year with lower values in the first part of the winter. Maximum values of suicide attempts are predominantly found in the afternoon and evening hours. There is a relative decline of suicide attempts in the last 2-3 months of the year.
conclusion Although a certain similarity in terms of seasonal distribution between suicides and suicide attempts was found, the differences in the 24 h distribution throughout the year are impressive. This observation would support the idea that in non-fatal suicidal behaviour psychosocial factors play a more dominant role than in fatal suicidal behaviour.