Data were gathered on a statewide basis in 102 Illinois counties on both the incidence and prevalence of adolescent public psychiatric hospitalizations and the identified self-destructive behaviors: (1) completed suicides; (2) assaultive behaviors; (3) runaway behavior; (4) substance abuse; and (5) teenage births, from fiscal year 1985 through fiscal year 1988. Data were analyzed to examine whether there was any relationship between mental illness severe enough to require psychiatric hospitalization and suicide and other self-destructive behaviors. It was hypothesized that there should be significant correlations between psychiatric hospitalization rates in a particular county and suicide rates. It was further hypothesized that completed suicides are only one of a continuum of adolescent self-destructive behaviors rather than being specifically related to psychiatric disorders. Analysis revealed only one year (FY86) wherein a significant correlation (p<.05) existed between public psychiatric hospitalization rank by rates and suicide rank by rates, whereas significant correlations (p<.01 + p<.05) were found between psychiatric hospitalization and substance abuse, teenage births, assaultive behaviors, and runaway behaviors in all years examined. (Author/NB)