"The NCS-R is one of 30 national surveys being done around the world in conjunction with the World Health Organization's World Mental Health Survey initiative. The NCS-R was the first of them, but there are also surveys in most of the major Western European countries, several countries in Eastern Europe, Africa, Asia, every region of the world," Kessler said. "More than a quarter of a million people are being interviewed with this instrument. And we have a consortium of researchers in these various countries that are coming together and analyzing these data collaboratively."
In the United States, the NCS-R is just one part of a coordinated program of new psychiatric epidemiological studies that will be completed over the next several years, according to Kessler. These include the NCS-A study of adolescent mental health in the United States; the NCS-2, a 10-year follow-up of the original NCS; the National Study of African American Life, and the National Study of Latino and Asian Americans.
The NCS was a nationally representative household survey of DSM-III-R disorders in the three-year time span from 1990 to 1992.
The NCS-2 is a follow-up survey of 4,375 NCS respondents (76.6% conditional response rate) reinterviewed in 2000 through 2002. The NCS-2 outcomes include hospitalization for mental health or substance disorders, work disability due to these disorders, suicide attempts, and serious mental illness.
"In the NCS-2, we are asking what happened to those 18-year-olds now that they are 28. How many of them are still depressed, have recovered or have gotten worse? So we are doing the life history kind of story," Kessler said.
Reports are now emerging for the NCS-2. One report looking at level of severity was published in the Archives of General Psychiatry (Kessler et al., 2003).
"We looked at people who were mild cases 10 years ago to see what happened to them, and we found a lot of them have substantial problems today," Kessler said. "The question is, is there something we could do to nip things in the bud, to treat [such individuals] while they still have a mild case?"
Asked about the adolescent study, Kessler said it is difficult to see disorders declaring themselves in young children, whereas in the adolescent years, "you can start seeing depression, substance problems and so forth. So we are quite interested in looking descriptively at what the prevalence, severity and correlates of those disorders are, and also in using [these data] as a baseline for following this cohort over time as they enter adulthood," he said.