It refers to a recent CDC report, which I could not find on the cdc.gov site (if someone finds it, please put a link in the comments). Here is a link to a .pdf CDC Fact Sheet on suicide.
[Edit... added 2/20/2008, from additional info in comments]
Kudos to Bee! Thank you for finding the link to the Dec 14 2007 MMWR article.
Table 2 makes the point quite clearly.
From 1999 to 2004, the rate of identified suicides per 100,000 population in the 20-29 age group went from 12.3 to 12.4, a 1% increase.
The rate in the 45-54 age group went from 13.9 to 16.6, a 19% increase.
From the article: Among persons aged 45--54 years, the total injury mortality rate increased 24.5%, including an 87.0% increase in the mortality rate from unintentional poisoning (most commonly drug poisoning) and a 48.0% increase in suicide by hanging/suffocation...
[For the entire US population, i]ncreases in poisoning mortality accounted for 61.9% of the increase in unintentional injury, 28.0% of the increase in suicide, 81.2% of the increase in deaths from injury of undetermined intent, and 55.7% of the increase in total injury mortality.
The authors suggest that the increase in poisoning is mostly due to an increase in substance abuse. 6% of the poisonings were due to "psychoterapeutic drugs", while 47% were due to narcotics and hallucinogens [Table 2].
I note that Maryland is one of the 4 states that actually recorded a decrease in overall population poisoning deaths for this time period (hmm, despite Baltimore being the Heroin Capital?).