Snippets from SAMHSA

In 2000, an estimated 4.7 million people aged 12 or older (2.1 percent of the  total population) needed treatment for an illicit drug abuse problem.
16.6 percent of the people who needed treatment in 2000, received Priority treatment services at a specialty facility.
Among Hispanic male admissions in 1999, alcohol was the most common primary substance of abuse(39%), followed by opiates (32%) and marijuana(14%).
In 1999, the most common primary substance of abuse among Hispanic female admissions was opiates (34%), followed by alcohol (26°/o) and cocaine (16%).
In 1999, opiates were the most common substance of abuse for Hispanic admissions aged 25-44, while alcohol was the most common substance of abuse for non-Hispanic admissions in the 25-44 age group.