Depression is linked to an elevated risk of STD infection for black men between the ages of 18 and 28, but not for their white peers or for women of either race, according to a study based on two waves of data from the National Longitudinal Study of Adolescent Health (Add Health).1 In adjusted analyses, the prevalence of STD infection was twice as high among young adult black men who were depressed as among those who were not; it was three times as high among those who were depressed both during adolescence and in young adulthood as among their young adult counterparts who were not depressed. Depression was associated with the likelihood that some subgroups of young men and women had had multiple partners, but was not related to condom use.
Add Health began with a nationally representative sample of students in grades 7–12 in 1995 and has followed them into young adulthood. To study the relationship between depression and both STD risk and sexual risk behavior, researchers analyzed data from Wave 1 and Wave 3 (conducted in 2001–2002). Both waves collected information on a wide array of participants’ characteristics and behaviors, and at Wave 3, respondents were asked to provide a urine sample, to be tested for chlamydia, gonorrhea and trichomoniasis. Black and white participants for whom sample weights were available and who had test results for all three STDs were included in the analyses. The researchers compared STD prevalence among various subgroups of these 8,794 young adults in bivariable analyses and then calculated prevalence ratios to assess relationships, for subgroups defined by sex and race, between depression and three outcomes: current STD infection, multiple partners in the past year and inconsistent condom use in the past year.
The sample was evenly divided between males and females, who were, on average, about 22 years old at Wave 3; eight in 10 were white, and the rest were black. Three-quarters had had vaginal intercourse by age 18, and 4% said at Wave 1 that they had had an STD. Mental health measures included in the survey suggested that 4% of young adults had major depression at both waves; these participants were categorized as having chronic depression. Seven percent were depressed only at Wave 3 and were classified as having had recent depression. Fewer than one in 10 had received counseling or been treated medically for depression or stress in the last year; the proportions were lower for blacks (10% and 5%, respectively) than for whites (21% and 17%).
At Wave 3, some 6% of respondents tested positive for an STD. The likelihood of having an infection was elevated among women (odds ratio, 1.6), blacks (7.0) and young adults with either chronic or recent depression (1.5 for each). It also was raised for those who were married, whose socioeconomic characteristics suggested some degree of disadvantage, who had first had intercourse at age 16 or earlier, and who reported having had an STD at Wave 1 (1.3–3.3).
In analyses that adjusted for potentially confounding socioeconomic and behavioral characteristics, both recently and chronically depressed black men were more likely to have an STD than were those with no depression detected at Wave 3 (prevalence ratios, 2.4 and 3.1, respectively). Depression was not associated with STD prevalence among white men or among black women; white women with chronic depression had a reduced prevalence of STD in young adulthood (0.2).
Associations between depression and having multiple partners were more common among women than among men. White women with recent depression were more likely than those with no depression to have had two or more, six or more, or 10 or more partners in the past year (odds ratios, 1.5, 2.1 and 6.9); those who were chronically depressed had elevated odds of reporting 10 or more partners (8.4). Black women with recent depression had elevated odds of having had at least six partners in the past year (2.6), and those with chronic depression had sharply reduced odds of reporting this outcome (0.1). No associations were found for white men, but black men with chronic depression were at risk of having had six or more partners (2.5) and 10 or more (2.2).
Neither inconsistent condom use nor nonuse of the method was associated with depression in any of the subgroups defined by sex and race.
"The most important limitation" of the study, in the researchers’ view, was that because of data constraints, it is not "fully longitudinal" and therefore does not permit assessment of causal relationships. Nonetheless, the investigators conclude that their findings highlight "the need for improved integration of mental health and [STD] diagnosis, treatment and prevention" services for young people, especially blacks. "Addressing depression," they remark, "may lead to improved physical health," including reduced STD risks.—D. Hollander
REFERENCE
1. Khan MR et al., Depression, sexually transmitted infection, and sexual risk behavior among young adults in the United States, Archives of Pediatrics and Adolescent Medicine, 2009, 163(7):644–652.