Objective. Early age of drinking onset has been associated with a greater likelihood among adults of experiencing alcohol dependence, frequent heavy drinking even among nondependent drinkers, and an increased risk of motor vehicle crashes, unintentional injuries, and physical fights after drinking. This study explores whether first getting drunk at a younger age is associated with a greater likelihood of college students reporting that they had unplanned or unprotected sexual intercourse because of their drinking.
Methodology. In 1999 11 739 full-time 4-year college students from 128 randomly selected US colleges and universities completed a self-administered survey that asked them about their drinking practices and whether their drinking had caused them, since the beginning of the school year, to: 1) engage in unplanned sexual intercourse or 2) not use protection when having sex.
Results. Among college students who drink, those first drunk before age 13 compared with those never drank until age 19 or older had a 2.0 times greater odds of having unplanned sex and a 2.2 times greater odds of having unprotected sex reportedly because of drinking, even after controlling for age, race/ethnicity, marital status, parental drinking history, age of first smoking, and marijuana use. After further controlling for history of alcohol dependence and frequency of heavy drinking those first drunk before age 13 had a 1.5 times greater odds of unplanned sex and a 1.7 times greater odds of unprotected sex reportedly because of drinking.
Conclusions. Clinical, educational, legal, and community interventions to delay age of first getting drunk need to be coupled with efforts to prevent unplanned and unprotected sexual intercourse among US college students.
Drinking alcohol to intoxication (getting drunk) may increase the likelihood that adolescents and young adults engage in sexual behavior that increases the likelihood of unplanned pregnancy and the incidence of sexually transmitted infections (STIs).1–4 Adolescents report they are more likely to have unplanned sexual intercourse when they or a potential partner has been drinking.4 Moreover, young persons who are sexually active are more likely to have unprotected sex when they have intercourse after drinking than when they have intercourse when they have not been drinking.1–4
Annually >900 000 adolescents become pregnant in the United States, and most teen pregnancies are unplanned.5 In the United States in 1998 there were 607 602 reported cases of chlamydia, 305 642 cases of gonorrhea, and 6993 cases of syphilis.6 Adolescents and young adults have higher rates of STIs than older adults.6 STIs common among adolescents are believed to facilitate human immunodeficiency virus (HIV) infection.7 In the United States 138 153 cases of acquired immunodeficiency syndrome (AIDS) between the ages of 13 and 29 have been reported, 17% of all cases.8 It is likely that most young adults who develop AIDS acquired HIV infection during their adolescent years.7
Starting to drink at younger ages has been associated with heavier drinking patterns later in life. A recent analysis of the National Longitudinal Alcohol Epidemiologic Survey (NLAES) found that the younger people were when they started drinking, the more likely they were to have experienced alcohol dependence during their life9 as measured by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria (DSM-IV).10 Among both males and females and persons with and without a family history of alcoholism, persons who began drinking before age 14 were at least 3 times more likely than those who did not drink until they were over 21 to experience diagnosable alcohol dependence during their life.9 Subsequent analyses of NLAES have revealed that even after controlling for personal history of alcohol dependence, people who started drinking at an earlier age drink heavily with greater frequency during both adolescence and adulthood.11
An association between alcohol use and unintentional injuries,12,13 motor vehicle crashes,14–16 and violent aggressive behavior17 has long been noted. Recent analyses further indicate that the younger people are when they start drinking, the greater their likelihood of experiencing alcohol-related unintentional injuries11 and motor vehicle crash involvement after drinking18 as well as being involved in physical fights after drinking,19 even after controlling for frequency of heavy drinking, personal history of alcohol dependence, and other characteristics related to the age at which respondents began drinking. The average age of respondents in this national survey was 44 years of age. Yet relations found between early age of drinking onset and alcohol-related injuries, motor vehicle crashes, and fights after drinking were found not only over a respondent’s entire life course but also during the year before the survey when most respondents were over age 21.
Whether getting drunk at an earlier age is related to a higher likelihood of experiencing unplanned and unprotected sex because of drinking among adolescents and young adults has not yet been explored. The purpose of this paper was to assess whether starting to drink alcohol to intoxication at younger ages increases the likelihood that college students (both younger than and older than 21 years) will report having unplanned and unprotected sex because of their drinking.
This study examines information collected by the 1999 Harvard College Alcohol Study (CAS).20 In 1993 a sample of 140 colleges was selected from a list of accredited 4-year colleges provided by the American Council on Education.21 The sample was selected using probability sampling proportionate to the size of the undergraduate enrollment at each institution. At each college a random sample of 225 undergraduates was drawn from the total enrollment of full-time students. The surveys were repeated in 1997 and 1999. In 1999, 128 schools from the original list of 140 colleges in the original 1993 Harvard College Alcohol Survey were resurveyed. In 1999 student samples at each institution were obtained using the same procedures used in the 1993 survey. Twelve schools were dropped from the original 1993 sample primarily because of the college administrators’ inability to provide a random sample of students and their mailing addresses within time requirements of the study.
Schools had to meet minimal response rate criteria to be included in this study: a response rate of at least 50% in 2 of the 3 surveys and a rate of at least 40% in the third. A total of 119 schools located in 40 states were included in the analyses. Dropping the 9 colleges did not change the rates of binge or heavy episodic drinking of the remaining sample (defined as 5 or more drinks in a row for men and 4 or more for women). The 119 schools represent a national cross-section of 4-year colleges. Two-thirds are public institutions and one-third are private. Forty-four percent have enrollments of 10 000 or more students, 23% have between 5001 and 10 000 students, and 34% have 5000 or fewer. Two-thirds are in suburban or urban settings. Fifteen percent are affiliated with a religious denomination and 5% enroll women only. Overall, 14 138 students completed the mailed, self-administered survey in 1999, and the response rate was 60%.
The survey asked the respondents, “How old were you when you first got drunk?” Response categories were age 9 or younger, 10 to 12, 13 to 15, 16, 17, 18, 19 or older, or “never did this.” Because of the small numbers first drank before age 10 that group was combined in the analysis with those who first drank to intoxication before age 13. Heavy episodic or binge drinking was defined as the consumption of at least 5 drinks in a row for men and 4 drinks in a row for women during the 2 weeks before the study.22 Drinks were defined as a 12-oz bottle or can of beer, a 4-oz glass of wine, a 12-oz bottle of wine cooler, or a shot (1.25-oz) of liquor, straight or in a mixed drink.
Embedded in the questionnaire were items adapted from the Semi-Structured Assessment for the Genetics of Alcoholism,23,24 which were designed to elicit self-report of DSM-IV criteria for a diagnosis of alcohol abuse or dependence during the year preceding the survey (ie, 12-month diagnosis).10 Among all college students in the 1999 CAS, 6% met DSM-IV criteria.25
Diagnosis of alcohol dependence based on DSM-IV criteria required that in any 1 year a respondent must meet at least 3 of 7 criteria: 1) tolerance; 2) withdrawal or avoidance of withdrawal; 3) persistent desire or unsuccessful efforts to quit; 4) spending much time drinking, obtaining alcohol, or recovering from its effect; 5) giving up or reducing occupational, social, or recreational activities in favor of drinking; 6) impaired control over drinking; and 7) continuing to drink despite a physical or psychological problem caused or exacerbated by drinking.7
Respondents were also asked, “Since the beginning of the school year, how often has your drinking caused you to: 1) engage in unplanned sexual intercourse? 2) not use protection when you had sex?”
The significance of relationships between age of first getting drunk and personal demographics and behavioral characteristics were tested using χ2. Logistic regression tested the significance of the relationship between age of first being drunk and the following dichotomous outcomes:
Past year drinking caused you to have unplanned sexual activity
Past year drinking caused you to not use protection when you had sex
Odds ratios and 95% confidence intervals were provided, comparing those in each age category at which respondents first reported getting drunk (before age 13, 13–15, 16, 17, and 18) with those respondents who did not drink to intoxication until age 19 or older.
Because the oldest age category respondents reported getting drunk was 19 or older we included in our analysis only college students 19 and older (N = 11 739). We entered into the logistic regression analyses variables significantly related to age of first intoxication: current diagnosis of alcohol dependence, frequency of binge drinking, age, sex, race/ethnicity, age respondents first smoked regularly, age of first marijuana use, family history of alcoholism, and marital status. This was done to control for potential confounding posed by these variables. Logistic regression analyses included only respondents who drank in the past year and who at some time drank to intoxication (N = 8657). Persons who never were drunk rarely reported unplanned or unprotected sex because of drinking, and were accordingly excluded from the analysis. We also conducted regressions not entering frequency of binging and dependence as covariates. Odds ratios in the 2 sets of regressions were compared with assess whether current dependence and binge drinking might account for part of possible relationships between early age of first getting drunk and study outcomes.
In 1999, 9% of students age 19 or older who had consumed alcohol in the past year met DSM-IV criteria for alcohol dependence and 54% binged during the 2 weeks before the survey. Twenty percent reported having unplanned sex and 10% reported having unprotected sex because of drinking since the beginning of the school year.
Of respondents age 19 or older in the CAS who drank, 1% said they first were drunk at age 9 or younger, 2% at ages 10 to 12, 20% at ages 13 to 15, 19% at age 16, 14% at age 17, 18% at age 19, and 16% at age 19 or older. Eleven percent of college students 19 or older who drank alcohol in the CAS said they never drank to intoxication.
Several personal and demographic characteristics were related to the age at which respondents first were drunk. Younger respondents, males, whites, persons never married, respondents who started smoking cigarette and who used marijuana at an earlier age, respondents whose parents did not disapprove of alcohol or who had at least 1 parent who was a heavy or problem drinker, all were more likely to get drunk at an early age (data available on request). Also, as we shall detail below, persons who currently met DSM-IV criteria for alcohol dependence and those who reported binge drinking in the past two weeks, even after controlling for meeting DSM-IV dependence criteria, were more likely to have been drunk for the first time at an early age.
As can be seen in Fig 1, among college students who drink, the younger they were when they first reported being drunk, the more likely they were to meet diagnostic criteria for alcohol dependence. Even after controlling for age, gender, race/ethnicity, marital status, parental drinking history, and the age at which they started cigarette and marijuana use, the odds of meeting alcohol dependence criteria were 3.1 times greater for those first drunk before age 13 compared with drinkers who were first drunk at age 19 or older (Fig 2).
Similarly, those first drank at younger ages were more likely than those never drank to report binge (heavy episodic) drinking (Fig 3). In addition, the relationship persisted even after controlling for alcohol dependence and the other characteristics cited above that were related to the age at which respondents were first drunk (Fig 4). Respondents first drunk before age 13 had 2.1 times the odds of reporting recent binge (heavy episodic) drinking than college drinkers first drunk at age 19 or older.
Those respondents who were first drunk at earlier ages were more likely than college student drinkers who were never drunk to report having had unplanned sex and unprotected sex because of their drinking (Figs 5 and 6). In turn, those who drink but were never drunk were less likely than those first drunk at age 19 or older to report having unplanned sex because of drinking. After controlling for age, gender, race/ethnicity, marital status, parental drinking history, and age at first cigarette and marijuana use, those first drunk before age 13 compared with those never drunk until age 19 or older had 2.0 times the odds of having unplanned sex reported to be because of their drinking and 2.2 times the odds of having unprotected sex reportedly because of their drinking (Tables 1 and 2). Even after further controlling for frequency of binge drinking and alcohol dependence, relative to those first drunk at age 19 or older, those first drunk before age 13 had 1.5 times the odds of unplanned and 1.7 times the odds of unprotected sex reportedly because of drinking. Those who were first drunk in each age group 17 and younger were significantly more likely to report unplanned and unprotected sex because of drinking than respondents first drunk at age 19 or older. Generally, the earlier the onset of first being drunk, the greater the likelihood of saying they had unplanned and unprotected sex because of drinking. Odds ratios were lower in the models that further controlled for frequency of binge drinking and alcohol dependence. Binge drinking and alcohol dependence were each independently related to reporting unplanned and unprotected sex because of drinking. Thus, some but not all of the relationship between earlier age of first drunkenness and reports of having unplanned and unprotected sex because of drinking is attributable to alcohol dependence and frequent binge drinking.
Evaluations of the age at which people start to drink alcohol have revealed that early drinking onset is associated with increased risk of alcohol-related health and social problems among adults including alcohol dependence later in life,9 frequent heavy drinking even among nondependent persons,11 unintentional injuries under the influence,11 motor vehicle crashes because of drinking,18 and getting into physical fights after drinking.19 This study found that, among college students who drink, the younger respondents were when they first got drunk, the greater the likelihood that, in the past year, they had unplanned sex and unprotected sex that they reported to be attributable to drinking. Compared with drinkers who never got drunk before age 19, the younger respondents were when they first were drunk, the greater the likelihood they would report having unplanned and unprotected sex because of drinking, even after controlling for history of alcohol dependence, frequency of drinking, and numerous other characteristics associated with the age of first becoming drunk.
Several factors should be considered when interpreting study results. First, social desirability may have influenced results. Persons more willing to admit becoming drunk at an early age may be more willing to acknowledge unplanned and unprotected sex because of drinking. They may also be more likely to report drinking as an excuse or rationalization for engaging in risky sexual behavior. Social desirability biases also may result in underreporting of these behaviors. Of course, the self-administered questionnaires used in this study were completed anonymously to minimize social desirability reporting biases.
Second, the study was cross-sectional and older college students may have difficulty remembering their age when they were first drunk. Longitudinal studies are needed that ask adolescents when they were first drunk and then follow them into adulthood to explore risky sexual behaviors.
Third, the study relied on self-report of unplanned or unprotected sex. Respondents were not asked about consequences of unplanned and unprotected sex such as STIs, HIV infection, or unplanned pregnancy. Nor were their medical records checked to corroborate these potential consequences of unplanned and unprotected sex. Studies are needed that explore these consequences and corroborate them through medical records.
Fourth, the survey did not ask respondents about unplanned or unprotected sexual activity when they had not been drinking. It is possible that persons who begin getting drunk at an early age are greater risk-takers in general and would be more likely to report unplanned and unprotected sex even when they had not been drinking.
Fifth, the CAS achieved only a 60% response rate. Although this is as high as other national surveys that have asked college students about their drinking, it does raise questions about whether respondents differed from nonrespondents. To examine this, a short form of the questionnaire was sent to nonresponding students in 1999. There was no significant difference in rates of past-year alcohol use for those who answered the full questionnaire. Moreover, the rates of heavy episodic drinking and other substance use observed by the CAS were consistent with those obtained by other major national surveys such as the Monitoring the Future study.26 Unfortunately, comparisons between respondents to the entire and short survey were not made on variables such as unplanned and unprotected sex because of drinking.
Research is needed to examine why even when personal history of alcohol dependence and frequency of heavy drinking are controlled, those first drunk at younger ages are more likely to say that because of drinking they had unplanned and unprotected sex. Several explanations are possible. First, as mentioned above, persons who begin to drink or get drunk at earlier ages may be greater risk-takers in general. Of note, however, in this study the relationship between early age of first drunkenness and unplanned and unprotected sex persisted even after controlling for age of first cigarette and first marijuana use. Second, they may be less appreciative of risks associated with drinking and behaviors like having unplanned or unprotected sex. They may be less fearful of STIs or HIV infection and less concerned about unplanned pregnancy.
Third, people who start to drink to intoxication at an early age may be more prone to attribute unplanned or unprotected sex to their drinking. They may be more apt to use their drinking as an excuse for the risky behaviors they engage in. It should be noted that the CAS did not conduct separate studies to validate the wording that drinking “caused” unplanned or unprotected sex. Whether reports of having unplanned or unprotected sex because of drinking means that the behaviors were more likely to occur after drinking or would not have occurred without drinking is not known.
Fourth, people who are first drunk at an earlier age may be more likely to believe that potential partners will be more likely to have sex when they drink and drink heavily. Whether they deliberately seek relationships with potential partners who drink heavily or attempt intercourse with intoxicated partners warrants exploration. Whether those first drunk at younger ages are more likely to offer partners drinks or attempt to ply them into sexual intercourse with alcohol also warrants study.
Despite these unresolved questions, our findings underscore the need for physicians and other health care providers to query their patients about the age at which they began drinking and were first drunk, and to counsel them about the numerous risks to health that have now been found to be associated with early onset of drinking.
Research has shown that alcohol policies such as raising the legal drinking age and increasing the price of alcohol can reduce STI rates among adolescents.27 Alcohol treatment studies and brief intervention studies with college students and other adolescents have been shown to reduce drinking and related problems—particularly alcohol-related injuries.28–30 Alcohol treatment has also been associated with a reduction in unprotected sex.31
Community-based programs that use compliance check surveys to assess the extent of sales of alcohol to minors and that increase enforcement to prevent sales can reduce underage drinking and injuries,32,33 but their effects on unplanned or unprotected sex after drinking have not been established.
The results of this study point to a need to further explore the relationship between early age of first getting drunk and unplanned and unprotected sexual intercourse because of drinking. Furthermore, they add additional reasons to expand clinical, educational, legal, and community interventions to reduce drinking among adolescents and delay onset of first drunkenness.
- Stall R, McResnick L, Wiley J, Coates TJ, Ostrow DG. 1996 alcohol and drug use during sexual activity and compliance with safe sex guidelines for AIDS. Health Education Q.1996;13 :359– 371
- ↵Division of STD Prevention. Sexually Transmitted Disease Surveillance, 1998. Atlanta, GA: Department of Health and Human Services, Centers for Disease Control and Prevention; 1999
- ↵Department of Health and Human Services. Health United States, 2000, With Adolescent Health Chart Book. Washington, DC: Centers for Disease Control and Prevention, National Center for Health Statistics; 2000. DHHS Publ. No. 001232:72
- ↵Centers for Disease Control and Prevention, National Center for HIV, STD, and TB Prevention, Divisions of HIV/AIDS Prevention. HIV/AIDS Surveillance Report. Atlanta, GA: Centers for Disease Control and Prevention; 2001
- ↵American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. Washington, DC: American Psychiatric Association; 1994
- ↵Reiss AJ, Roth JA. Understanding and Preventing Violence. Washington, DC: National Academy Press; 1994
- ↵Hingson R, Heeren T, Zakocs R. Age of drinking onset and involvement in physical fights after drinking. Pediatrics.2001;108 :872– 877
- ↵Wechsler H, Nelson TF. Binge drinking and the American college student: what’s five drinks. Psychology Addict Behav.2001;15 :287– 291
- ↵Johnston L, O’Malley P, Bachman J. Monitoring the Future: National Survey Results on Drug Use 1975–1999, Volume II: College Students 19–40. Bethesda, MD: National Institute on Drug Abuse; 2000. NIH Publ. No. N0-00-4803
- ↵Wagenaar A, Murray D, Gelan J, et al. Communities mobilizing for change: outcomes from a randomized community trial. J Stud Alcohol.2000;161 :85– 94
- ↵Holder HD, Gruenewald PJ, Ponicki WR, et al. Effects of community-based interventions on high-risk driving and alcohol-related injuries. JAMA.2000;289 :2341– 2347
- Copyright © 2003 by the American Academy of Pediatrics