OPEN MINDS The Behavioral Health & Social Service Industry Analyst Industry Statistic Use of inpatient services for treatment of chemical dependency by CHAMPUS eligibles increased 280% from 1980 through 1988. This increase was led by a 634% in use of chemical dependency treatment among those in the 15- to-24 age group and a 752% increase in the 25-to-34 age group. This increase in inpatient chemical dependency services accounted for roughly 20% of the total increase in inpatient health care utilization during this time period. The chemical dependency utilization . . .