CORVALLIS, Ore. - Females who identify as sexual minorities face an increased risk of substance use that shows up as early as age 13, suggesting early adolescence is a critical period for prevention and intervention efforts, a new study from Oregon State University has found.
The odds of substance use among females who identify as sexual minorities - an umbrella term for those who identify with any sexual identity other than heterosexual or who report same-sex attraction or behavior - is 400% higher than their heterosexual female peers.
"We saw this striking difference in substance use at age 13 and there was rapid increase in the rate of cigarette and alcohol use from there," said Sarah Dermody, an assistant professor in the School of Psychological Science in OSU's College of Liberal Arts and the study's lead author. "That tells us we need to find ways to intervene as early as possible to help prevent substance use in this population."
The findings were published recently in the Journal of LGBT Youth. Co-authors are James McGinley of McGinley Statistical Consulting and director of behavioral analytics at the Vector Psychometric Group; Kristen Eckstrand, a physician at the University of Pittsburgh Medical Center; and Michael P. Marshal of the University of Pittsburgh.
Among youth, alcohol, marijuana and nicotine are the three most commonly used drugs. That is a concern because youth who use those substances are at risk of negative health and social outcomes, including addiction and poor cognitive, social and academic function.
Past research has shown that sexual minority youth reported nearly three times more substance use than heterosexual youth. The disparity may be due in part to stress from discrimination, violence and victimization rooted in their sexual minority status, Dermody said.
The pattern of increased substance use for youth who identify as sexual minorities is magnified significantly for females. In the new study, researchers hoped to gain better understanding of how substance use rates develop over time for this group in particular, Dermody said.
Using data from about 2,200 participants in the Pittsburgh Girls Study, a large, longitudinal study of the lives of urban girls, researchers examined substance use among females over time from age 13 to 20, comparing those who identified as heterosexual to those identifying as lesbian/gay or bisexual.
They looked at when disparities in use between heterosexual and sexual minority identifying females began to emerge; rates of change over time for both groups; and how rates change as the girls approach young adulthood.
The researchers found that disparities in substance use between heterosexual and sexual minority girls were already present at age 13. The difference in use between heterosexual and sexual minority girls persisted and increased as they entered their 20s.
The findings suggest that early prevention and intervention efforts may be needed to reduce initial use and slow the escalation of substance use among the population. Such efforts could also help decrease substance use disparities over time, Dermody said.
"It's already a risky and vulnerable period for youths' social development, and it's also a vulnerable time for brain development," Dermody said.
It's also important to remember that within the population of youths who identify as sexual minorities, there are many youths who are not using any substances at all, or who are not using them as heavily, Dermody said.
"This is a subgroup that we are concerned about," she said. "In future research, it would useful to explore how individual youths' experiences influence where they fall on the spectrum of substance use."