Clinicians and researchers have long observed that SUDs frequently affect multiple members within families over different generations. Researchers have found that approximately 50% of the risk of substance abuse or dependence in adolescence is genetically influenced.4 The transition between stages of use, from regular use to abuse and dependence is also genetically influenced, although the relative genetic contribution compared with environmental influences varies by substance.4 Young and colleagues5 found that a common genetic influence accounts for comorbid substance use during adolescence, specifically problem use of tobacco, alcohol(Drug information on alcohol), and cannabis.
Behavioral modeling of substance use through exposure to parental substance use early in life also accounts for part of the familial association in SUDs. The association between exposure to parental SUDs and the development of an SUD in offspring is consistent with social learning theory. A review by Petraitis and colleagues6 further described social learning theory as the hypothesis that children model their behavior on people who are important to them and those they frequently interact with, such as their parents. The researchers also reviewed social control theory, which hypothesizes that children who are closely attached to their parents are less likely to break rules because they want to connect with their parents. Children who are closely monitored by their parents and have clear rules are also more likely to conform to their parent’s rules and are less likely to act out by abusing substances.
There is evidence that supports the principles of social learning theory and social control theory. Researchers have examined components of both theories by assessing the relationship between adolescent substance use and parental attitudes toward substances, parental substance use, the quality of the relationship between parent and child, and parental monitoring. Bahr and colleagues7 found that the family factors that were most strongly associated with an increased prevalence of binge drinking, cigarette use, cannabis use, and illicit drug use were tolerant parental attitudes and sibling substance use. In addition, adolescents who had parents who were tolerant of substance use interacted with higher-risk peers and were more likely to have friends who were substance users.
Exposure to parental substance use increases children’s risk
To understand familial patterns of SUD, family-based research has focused on differentiating between risk mediated primarily by genetics from risk mediated primarily by behavioral modeling through exposure to parental SUD and delineating the risk posed by the combination of both. In a larger longitudinal study of predominantly males with and without ADHD, Biederman and colleagues8 found an association between exposure to parental SUD and SUD in offspring after controlling for both family history and ADHD.
We recently evaluated a predominantly female sample with and without ADHD.9 In this study of 552 individuals of whom 71% were female, a specific association was found between exposure to maternal drug use disorders (primarily cannabis) and drug use disorders in female offspring after controlling for family history and ADHD. In other words, mothers who abused drugs increased the likelihood that their daughters would also abuse drugs. Interestingly, research findings have not shown consistent sex patterns when the risk associated with exposure to parental substance abuse was examined.10,11 Our finding of a specific risk between mothers and daughters may reflect the greater impact that interpersonal relationships have on an adolescent girl’s risk of using substances relative to the risk in adolescent boys.12
It is also important to consider whether the developmental timing of exposure to parental substance use may influence the chances that the child will develop an SUD. For instance, Biederman and colleagues8 assessed offspring risk of developing an SUD connected with exposure to parental SUD during different developmental stages. Predominantly, boys were at significantly greater risk for developing an SUD when they were exposed to parental SUDs during adolescence than when they were exposed during preschool and latency years.
In our predominantly female sample, we also found that exposure to parental SUD during adolescence was specifically associated with an increased risk of developing an SUD.9 It is unclear why adolescents are particularly vulnerable to exposure to parental substance use; it may be that behavioral modeling of use at a time when adolescents have greater ease of access to substances partially accounts for their increased risk.
What is already known about familial influences and adolescent substance use disorders (SUDs)?
■ The development of adolescent-onset SUDs is influenced by both genetic and environmental risk factors. Familial environmental risk factors include behavioral modeling of substance use, parental attitudes toward substance use, and parental monitoring.
What new information does this article provide?
■ Adolescent girls exposed to maternal drug use disorders are at increased risk for developing a drug use disorder. Exposure to parental SUDs specifically during adolescence increases a child’s risk of developing an SUD.
What are the implications for psychiatric practice?
■ Practitioners may be able to prevent adolescent-onset SUDs by screening for parental SUDs and educating families about the risks associated with exposure to parental SUDs.
Opportunities to prevent adolescent SUD
While genetic risk for SUD is a nonmodifiable risk factor that influences the development of adolescent-onset SUD, exposure to parental SUD is something that can, theoretically, be changed. Psychiatrists may help decrease the risk of adolescent SUD by educating parents about the power of behavioral modeling. Many parents of adolescents, for instance, still smoke marijuana regularly without considering the consequences of such use on their children.
Clinicians should assess parents for substance use in a nonjudgmental manner.13 Brief interventions such as the Substance Abuse and Mental Health Services Administration’s recent screening, brief intervention, and referral to treatment (SBIRT) initiative have been shown to be effective in decreasing both alcohol and drug use.14 Parental screening and subsequent modifications in patterns of substance use may thus decrease the risk of development of SUDs in children.
CASE VIGNETTE
Kate, a 13-year-old girl with ADHD and general anxiety who you have been treating for 2 years, presents for a routine psychopharmacological appointment with her mother. Kate’s mother reports that things have been more stressful at home. You remember that the patient’s mother has a psychiatric history significant for previous marijuana dependence.
Because Kate’s mother has a history of marijuana dependence, it is important to privately check with her to ask about recent marijuana use as well as other substance use. Discuss with the mother how her marijuana use may increase her daughter’s risk for drug abuse.
CASE VIGNETTE
George, a 40-year-old father with depression who has a 10-year-old son and a 13-year-old daughter, presents with increasing alcohol use. Lately he has been passing out after drinking in the evening. George does not think that his drinking is a problem.
In this case, it may be useful to carefully query George about his perception of how his drinking is affecting his family. It would also be helpful to educate him about his adolescent daughter’s increased risk of substance use problems given her exposure to his choices and behavior patterns.
In addition to modifying an adolescent’s risk of developing an SUD by minimizing his or her exposure to a parent’s modeling substance use, clinicians can educate parents about the principles of social control theory. The risk of SUD onset is decreased in children whose parents know what their children are doing. Parental control also decreases the risk that the child will have friends who use alcohol or drugs.7
Conclusion
SUDs in adolescents interfere with emotional and cognitive development and can be associated with long-term medical and legal consequences. There is a substantial genetic influence on the development of SUDs. The aggregate data also show that other familial factors that can be modified, such as exposure to parental SUDs particularly during adolescence, are significant as well. Conscious efforts to screen for parental SUDs and educate families about exposure risk may help prevent the onset of substance abuse during adolescence.
