Rates of major depression and of major depression with comorbid substance use disorders are on the rise. A recent review that was conducted by Dr Wilson M. Compton and associates from the National Institutes of Health showed that the prevalence rates of major depression increased in patients with and without a substance use disorder from 3.33% in 1991-1992 to 7.06% in 2001-2002. The results of the survey were published in the December 2006 issue of The American Journal of Psychiatry.

The researchers used data from 2 major, nationally representative surveys: the National Longitudinal Alcohol Epidemiologic Survey (N = 42,862), conducted in 1991-1992, and the National Epidemiologic Survey on Alcohol and Related Conditions (N = 43,093), conducted in 2001-2002. All diagnoses were made based on data from the Alcohol Use Disorder and Associated Disabilities Interview Schedule—DSM-IV.

Increases in major depression, with or without a substance use disorder, were statistically significant for white, black, and Hispanic persons and for all age groups.

Rates of major depressive episodes within the past year in patients with a current substance use disorder increased from 9.97% in 1991-1992 to 15.06% in 2001-2002. Significant increases were reported in whites and blacks of every age group, including in white and black women. Young black men (aged 18 to 29 years) were the only group in which a statistically significant increase in depression could be explained by an increase in co-occurring substance use disorders.

In persons without a substance use disorder, the rates of depression increased from 2.76% in 1991-1992 to 6.23% in 2001-2002.

The authors noted that a general change in patients' willingness to report depressive symptoms is not likely to explain the increased rates of depression found in the studies, and they suggested that a number of environmental factors need to be studied to clarify their potential role in increasing the rates. They also warned of potentially profound economic and health care implications if rates continue to rise at the same pace as did over the decade studied.