Prevalence, Severity, and Comorbidity of 12-Month DSM-IV Disorders in the National Comorbidity Survey Replication
Kessler RC, Chiu WT, Demler O and Walters EE;
Commented by , 16 Jun 2005
Background
During the eighties and nineties, major epidemiological studies have revealed very high prevalence rates for DSM-III and DSM-III-R mental disorders in the general population. The validity as well as the clinical significance of these rates have, however, been questioned.
Aims of the study
To establish prevalence rates for DSM-IV mental disorders in the general population, to compare those rates with those found in previous investigations, and to closely examine the validity and clinical significance of those rates.
Method
A nationally representative survey using a fully structured diagnostic interview, the World Health Organization World Mental Health Survey Initiative version of the Composite International Diagnostic Interview or WMH-CIDI.
Results
Twelve-month prevalence of any disorder was 26.2%. Anxiety disorders were the most prevalent class (18.1%), followed by mood disorders (9.5%), impulse control disorders (8.9), and substance use disorders (3.8%). Among respondents with a disorder, 22.3% were classified as serious, 37.3% as moderate, and 40% as mild.
Professor Pull's comments
The results of the NCS-R confirm that mental disorders are highly prevalent in the general population. 12 month prevalence rates are consistent with those of previous community surveys in the United States. High prevalence rates in previous epidemiological studies have led to speculations that lay-administered diagnostic interviews lead to results that are artificially inflated.
In fact, blind clinical re-interviews with the Structured Clinical Interview for DSM-IV (SCID) generally were in good accordance with WMH-CIDI diagnoses. High prevalence rates also have led to suggestions that many community cases are mild. The results of the study confirm these assumptions.
Although DSM-IV puts greater emphasis on clinically significant distress and impairment than earlier editions of the DSM, only 5.7% (22.3% of the 26.2% overall prevalence) of cases meeting criteria for a 12-month DSM-IV disorder were identified as serious.
The 5.7 % of respondents with serious mental disorder over the past 12 months is, however, still substantial. Serious cases were concentrated among a relatively small proportion of cases with high comorbidity.
Three other articles (ref. 1; ref. 2; ref. 3) in the June issue of the General Archives of Psychiatry, present additional initial results of the National Comorbidity Study Replication (NCS-R).
The first article (ref. 1) presents life-time prevalences of mental disorder. The results suggest that about half of the American population (46%) will meet the criteria for a DSM-IV disorder in their life. Anxiety disorders were the most prevalent class (28.8%), followed by mood disorders (20.8%), impulse control disorders (24.8%), and substance use disorders (14.6%).
As shown by the results of the second article (ref. 2) the vast majority of people with a DSM-IV diagnosis of mental disorder will eventually seek treatment, although in most cases after prolonged delays, ranging from 6 and 8 years for mood disorders and 8 and 23 years for anxiety disorders.
The third article presents data showing that the majority of 12 month cases remain untreated or undertreated (ref. 3). The results of these two last articles suggest that there is a need for better patient information and higher quality of treatment in the field of mental disorders.
References
1. Kessler RC, Berglund P, Demler O, Jin R, Merikangas KR, Walters EE. Lifetime Prevalence and Age-of-Onset Distributions of DSM-IV Disorders in the National Comorbidity Survey Replication. Arch Gen Psychiatry 2005; 62 (6); 593-602
2. Wang PS, Berglund P, Olfson M, Pincus HA, Wells KB, Kessler RC. Failure and Delay in Initial Treatment Contact After First Onset of Mental Disorders in the National Comorbidity Survey Replication. Arch Gen Psychiatry 2005; 62 (6); 603-613
3. Wang, PS, Lane M, Olfson M, Pincus, HA, Wells K, Kessler RC. Twelve-Month Use of Mental Health Services in the United States: Results From the National Comorbidity Survey Replication. Arch Gen Psychiatry 2005; 62 (6); 629-640