New government figures show a surprising increase in US youth suicides after a decade of decline, and some mental health experts think a drop in the use of antidepressant drugs may be to blame. Suicides climbed 18 percent from 2003 to 2004 for Americans under age 20, from 1,737 to 1,985 deaths. Most suicides occurred in older teens, according to the data - the most current to date from the federal Centers for Disease Control and Prevention. By contrast, the suicide rate among 15- to 19-year-olds fell in previous years, from about 11 per 100,000 in 1990 to 7.3 per 100,000 in 2003. Suicides were the only cause of death that increased for children through age 19 from 2003-04, according to a CDC report released Monday.