In the United States, marijuana use by adults has increased in recent years.
Adolescents whose parents use the drug may be at higher risk of substance abuse, according to results of a new nationwide study.
The findings, published in JAMA Network Open, are from a cross-sectional study based on survey data from the 2015 to 2018 National Survey on Drug Use and Health (NS-DUH).
Conducted by the Substance Abuse and Mental Health Services Administration (SAMSHA), NSDUH was designed to be nationally representative of substance use among the US civilian, noninstitutionalized population aged 12 years and older.
Participants surveyed were adolescents aged 12 to 17 who lived with a sampled parent born between 1955 and 1984 and young adults aged 18 to 30 living with a samples parent born between 1955 and 1980.
A maximum of two people were selected for the survey from any one dwelling unit, meaning that a child and both parents living in the same home were never all included. During the interviews, which lasted approximately 1 hour, the researchers collected information on lifetime use and past-year use of tobacco, alcohol, and illicit drugs (i.e. marijuana, cocaine, heroin, hallucinogens, inhalants, and methamphetamine) and misuse of prescription opioids, stimulants, sedatives, and tranquilizers.
Parental use of marijuana was assessed at four levels: never use, lifetime use, less than 52 days of past-year use, and 52 days or more of past-year use.
A total of 24,900 mother-offspring or father-offspring dyads were surveyed. Of the mothers living with adolescent off spring, 8.2% (95% CI, 7.3% to 9.2%) had used marijuana in the past year while 7.6% (95% CI, 6.2% to 9.2%) of mothers living with young adult offspring, compared with 9.6% and 9.0% of fathers, respectively.
Past-year marijuana use of was higher in adolescents whose mothers had lifetime marijuana use than in those whose mothers never used the drug (ARR 1.3; 95% CI, 1.1 to 1.6; P = .007), less than 52 days of past-year marijuana use (ARR 1.7; 95% CI, 1.1 to 2.7; P = .02), or 52 days or more of past year marijuana use (ARR 1.5; 95%CI, 1.1 to 2.2; P =.02). Similar trends were seen among young adults (P = .001, P = .049 and P = .002, respectively).
Looking at the father-offspring dy-ads, the authors found that adolescents whose fathers had less than 52 days of past-marijuana use were more likely to use marijuana than those whose fathers never used marijuana (ARR 1.8; 95% CI 1.2 to 2.7; P = .006).
Compared with young adults whose fathers never used marijuana, young adults whose fathers had 52 days or more of past-year marijuana use were more likely to use marijuana (ARR 2.1; 95% CI 1.6 to 2.9; P < .001).
Compared with their peers whose parents never used marijuana and after adjusting for covariates, adolescents whose mothers had lifetime marijuana use had a higher adjusted risks of past-year tobacco use, past-year marijuana use, or 52 days or more of past-year marijuana use (ARR 1.3; 95% CI 1.0 to 1.6; P = .03, ARR 1.5; 95% CI 1.0 to 2.1; P = .04, and ARR 1.6; 95% CI 1.1 to 2.3; P = .03, respectively).
The adjusted risk was also higher for young adults whose mothers had lifetime marijuana use (ARR 1.2; 95% CI 1.0 to 1.5; P = .04). Compared with their peers whose parents had no past marijuana use and after adjusting for covariates, risk of past-year alcohol use was higher among adolescents whose mothers had lifetime marijuana use (ARR 12; 95% CI 1.1 to 1.4; P = .004) less than 52 days of past-year marijuana use (ARR 1.5; 95% CI 1.2 to 1.9; P = .002) or 52 days or more of past-year marijuana use (ARR 1.3; 95% CI 1.0 to 1.7; P = .04).
After adjusting for covariates, parental marijuana use was not associated with opioid misuse by off spring.