The occurrence of completed suicide by age in 1-year age groups in adolescence & young adulthood was studied via official Finnish mortality statistics & population statistics. Suicide rates increased sharply by age during adolescence, starting somewhat earlier among boys than among girls. During the periods of rapidly rising & high suicide rates in the 1970s & 1980s among boys, the increase in suicide rates started at a younger age than during a spell of lower rates in the 1960s. (26 refs.)