Adolescents who use alcohol, cigarettes and marijuana while alone are more likely to have health and behavioral problems as young adults than their peers who consume the substances only in social settings, according to a RAND Corporation study issued today.
Solitary alcohol, cigarette and marijuana users are less likely to graduate from college, more likely to have substance use problems as young adults, and tend to report poorer physical health by age 23 than their peers who were social substance users, according to the study by the nonprofit research organization.
"While substance use is a problem in itself, these findings suggest that risk among solitary users is especially high," said Joan Tucker, a RAND psychologist and lead author of the study. "Solitary use is a warning sign that youth will be less productive and have more problems as young adults -- more problems, even, than others who also used substances during childhood. The challenge is to identify these at-risk children and find out what type of assistance might benefit them."
Among the 8th graders studied, 16 percent had smoked cigarettes while alone, 17 percent had engaged in solitary drinking and 4 percent had used marijuana while alone.
Prior research has found that adolescent substance users are at risk for a wide range of problems during adolescence that persist into young adulthood, such as low academic achievement, stealing and other social problems.
The RAND Health study, published in the December edition of the journal Psychology of Addictive Behaviors, is the first to study adolescent solitary substance users and track their functioning over time.
The results come from a study of about 6,000 adolescents from California and Oregon enrolled in a program to evaluate Project ALERT, a drug use prevention program developed by RAND for middle school children. People involved in the study were asked about their substance use and a variety of other issues several times during middle school and high school, and again at age 23.
Researchers found that during adolescence, those who used alcohol, cigarettes and marijuana alone were at higher risk for a variety of troubling behaviors as compared with social-only users. Solitary users admitted to more delinquent behavior, such as stealing and acting out at school, and were less inclined to talk to their parents about personal problems.
Solitary users also were less engaged with school. This was evidenced by their lower grades, less time spent on homework and less time devoted to school activities. However, solitary users spent significantly more time going to parties and dating than other substance-using youth.
"This dispels the notion that these solitary users are lonely, socially isolated teens," Tucker said.
Consistent with their active social life, solitary substance users typically felt that substance use has positive effects on their behavior, allowing them to relax, have more fun, and get away from their problems. In contrast, they were less likely than social-only users to think substance use is harmful -- that it impairs physical and cognitive functioning, and factors into behavioral problems.
In addition, solitary users reported higher frequency and quantity of substance use compared to social-only users. On average:
Solitary users in 8th grade reported using alcohol, cigarettes or marijuana three to five days in the past month. On the days they used the substances, they smoked three to seven cigarettes, had two to three alcoholic drinks, or smoked marijuana three or more times.
Social-only users in 8th grade reported using substances less than one to two days in the past month. On the days they used the substances, they smoked one to two cigarettes, had one drink, or smoked marijuana twice.