The death rate for 15-24 yr olds has risen whle there has been a reduction in mortality for all other age groups. To analyze the geographic pattern of this youthful suicide epidemic, an national interstate analysis was done for the years 1964-78. Statistical analysis shows a strong inverse relationship between youthful suicide and population density. These undercrowding effects may occur because of social isolation, limited social services and loneliness. 15 ref.