DSM-5 Substance Use Disorders Among College-Age Young Adults in the United States: Prevalence, Remission and Treatment

Abstract

Objective:

To determine the prevalence, remission, and treatment associated with DSM-5 substance use disorders (SUDs) among young adults based on college attendance.

Participants:

The population-based sample included 2,057 young adults aged 19–23 in college/school and 1,213 not currently attending college/school who participated from April 2012 through June 2013.

Methods:

Face-to-face interviews were conducted as part of a cross-sectional national survey.

Results:

The prevalence of any past-year DSM-5 SUD was 39.6% among young adults in college and 44.5% among those not attending college. Past-year tobacco use disorder and multiple DSM-5 SUDs were more prevalent among those not attending college. Among those with prior-to-past-year SUDs, abstinent remission was low among college (1.0%) and non-college (1.9%) young adults.

Conclusions:

Approximately two in five U.S. college students had at least one past-year DSM-5 SUD. Sustained abstinent remission from SUDs is extremely rare (1–2%) and the majority of those with SUDs do not receive treatment.

1. Introduction

Substance use disorders (SUDs) are most prevalent among young adults and represent a major source of morbidity and mortality.^1–3 Previous research has examined differences in mental health and substance use among young adults as a function of educational status.^4–6 Non-college young adults tend to have higher rates of cigarette smoking, cannabis use, nicotine dependence and non-alcohol or other illicit drug use disorders than those attending college.^4,5 In contrast, college students have been shown to have higher rates of binge drinking and nonmedical use of prescription stimulants than non-college young adults.^5,7

The most recent edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM–5) does not contain a diagnosis for meeting criteria of multiple SUDs despite the high rates of polysubstance use among young adults.^8,9 Prior studies examining SUDs among college students often focus on substance-specific diagnoses rather than taking a polysubstance perspective.⁸ The past omission of multiple SUD diagnoses created a significant gap in knowledge, which is problematic since multiple SUDs have been shown to be most prevalent among young adults and have a more persistent course of disease over time relative to individual SUDs.⁹ To date, there are no national estimates of DSM-5 substance-specific and multiple DSM-5 SUDs among young adults or college students.

Epidemiological studies have found notable differences associated with young adults, sex, and sexual orientation in the prevalence of SUD and substantial comorbidity between substance-specific SUDs and other psychiatric disorders.^1,2 While young adults have the highest rates of SUDs, there is a paucity of research examining the remission from DSM-5 SUDs among U.S. college students.¹⁰ Although studies have examined the developmental course of heavy drinking and other drug use during the transition from adolescence to adulthood,^11,12 the prevalence of remission (i.e., specified period of time (e.g., past 12 months) in an individual’s life characterized by either abstinence (no substance use) or current non-disordered use) from DSM-5 SUDs among college students remains largely unknown.^12,13

Young adults in the U.S. have very low rates of SUD treatment despite considerable need for treatment.^6,14–17 Based on the high rates of polysubstance use, low levels of treatment seeking, and high need for SUD treatment among college students, it seems important to examine remission from substance-specific SUDs and remission from multiple SUDs. While there is evidence that college students are less likely to receive SUD treatment for alcohol use disorders (AUD) than their non-college peers,^4,6 the extent to which this finding extends to non-alcohol SUDs and multiple SUDs remains unclear. The current study fills important gaps in knowledge by examining the prevalence, correlates (e.g., race/ethnicity, sexual orientation, and psychiatric disorders), remission, and treatment associated with DSM-5 substance-specific SUDs (e.g., AUD) and multiple DSM-5 SUDs (e.g., alcohol and cannabis use disorders) among college students in relation to non-college peers.

2. Methods

2.1. Study Design

The present study used the 2012–2013 National Epidemiologic Survey on Alcohol and Related Conditions-III (NESARC-III) as the primary source of information regarding DSM-5 SUDs among the civilian noninstitutionalized population of individuals 18 years of age and older in the U.S. Probability sampling was used for random selection of participants and included a random sample of eligible adults within households: individual counties and groups of contiguous counties were the primary sampling units, secondary sampling units were identified through groups of U.S. Census-defined blocks, and tertiary sampling units were households within the secondary sampling units.¹ In-person interviews were conducted, and the household, person, and overall response rates were 72%, 84%, and 60.1%, respectively. The sample included persons living in households, military personnel living off base, and persons residing in group quarters: boarding or rooming houses, non-transient hotels, shelters, facilities for housing workers, college quarters and group homes. Hispanic, African-American, and Asian respondents were oversampled, and when at least 4 eligible individuals lived in the household, two participants were selected.¹ The sample design and weighting procedures, which adjust for potential biases introduced by nonresponse, have been described in more detail elsewhere.^1,18 Procedures received institutional review board approval and relevant ethical safeguards have been met by the NESARC-III and our research teams in relation to human subject protection.

2.2. Participants

The NESARC-III sample consisted of 2,057 college students and 1,213 non-college peers aged 19–23 with a mean age of 20.92 (SE=0.04) and 21.49 (SE=0.04), respectively. A majority were female (college: 50.42%), male (non-college: 52.02%), non-married (college: 94.33%; non-college: 87.68%), U.S. born (college: 88.7%; non-college: 88.91%), living in an urban area (college: 87.58%: non-college: 81.03%), in the geographic region of the South (college: 35.48%; non-college: 37.64%), and had an income below $20,000 (college: 42.94%; non-college: 40.09%). Sexual orientation was as follows, heterosexual (college: 93.23%; non-college: 91.51%), bisexual (college: 3.33%; non-college: 4.43%), gay or lesbian (college: 2.20%; non-college: 2.08%), 1.23% (college) and 1.99% (non-college) responded as not sure or were missing a response. Race and ethnicity rates were White (college: 57.97%; non-college: 56.36%), Hispanic (college: 17.35%; non-college: 24.68%), African-American (college: 15.13%; non-college: 13.85%), Asian (college: 8.00%; non-college: 2.80%), 1.55% (college) and 2.30% (non-college) endorsed other racial/ethnic categories. In the total sample, 147 respondents reported minority sexual orientation status. There were significant (all p<.001) differences between college and non-college peers in relation to Hispanic ethnicity, being married, living in a rural area, and having an income of $70,000 or higher. These significant differences highlight the importance of controlling for these factors in subsequent analyses.

2.3. Measures

The measures in the Alcohol Use Disorder and Associated Disabilities Interview Schedule-5 (AUDADIS-5) assessed sociodemographic characteristics, DSM-5 SUDs, substance use treatment, and other psychiatric disorders.

Sociodemographic characteristics

were measured, including sex, age, race/ethnicity, marital status, urbanicity, nativity, family income, geographical region, sexual orientation, and educational status in the past year. Based on prior work,^4,5 college educational status was derived from the following response options: enrolled in college/school full-time, part-time, currently on summer break/holiday from college/school, or not enrolled currently nor in the past year as a full-time or part-time student

DSM-5 SUDs

were assessed according to DSM-5 criteria using the AUDADIS-5, including substance-specific diagnoses for eleven substances: alcohol, tobacco, cannabis, cocaine, heroin, hallucinogens, inhalants, prescription opioids, prescription sedatives/tranquilizers, prescription stimulants, and other drugs (e.g., ecstasy, ketamine). Substance-specific diagnoses were made for past-year and prior-to-past-year (prior). Consistent with the DSM-5, each substance-specific SUD diagnosis required positive responses for two or more of the 11 criteria within the same 12-month period. Substance-specific abstinent remission from SUD was defined as not engaging in substance-specific use nor meeting criteria for substance-specific SUD for at least the past 12 months among those who met criteria for at least one prior SUD (e.g., no past-year alcohol use for someone with a prior AUD). Based on the polysubstance use and multiple SUD focus in the current study, any substance abstinent remission from SUD was defined as not engaging in any substance use nor meeting criteria for any SUD for at least the past 12 months among those who met criteria for at least one prior SUD (e.g., no past-year cocaine use for someone with a prior AUD). The reliability and validity of AUDADIS-5 DSM-5 SUD diagnoses have been examined in psychometric studies, with reliability ranging from fair to good and dimensional criteria scales (intraclass correlation coefficient=0.5–0.9, respectively) ranging from fair to excellent in a large general population sample.^1,2,18–20

DSM-5 other psychiatric disorders

were assessed using the AUDADIS-5, including lifetime anxiety disorders (i.e., agoraphobia, generalized anxiety disorder, panic, social and specific phobias), mood disorders (i.e., bipolar, dysthymia, major depressive disorder), eating disorders (i.e., anorexia nervosa, binge-eating, bulimia nervosa), and personality disorders (i.e., antisocial, borderline, schizotypal). Consistent with the DSM-5, all diagnoses excluded substance-induced and medical illness-induced disorders. Reliability and validity of the DSM-5 based AUDADIS-5 diagnoses of other psychiatric disorders have been well established.^19,20

Substance use treatment

was assessed by asking respondents with a prior DSM-5 substance-specific SUD whether they had ever sought help for substance use. Alcohol treatment was defined as respondents attempting to get assistance with drinking from a wide range of resources including self-help groups, social services, substance use services, emergency rooms, or crisis centers. For other drug treatments, respondents were asked a separate series of questions related to 12-month drug treatment utilization that paralleled alcohol-related treatment.

2.4. Statistical Analysis

All analyses were design-based, as they accounted for the NESARC survey weights in estimation to generate representative population estimates of selected parameters (i.e., percentages, odds ratios). Standard errors for the weighted estimates and 95% confidence intervals for the parameters directly accounted for the stratified cluster sampling employed by the NESARC, as did all weighted Rao-Scott tests of association between two categorical variables. The svy: commands in Stata (Version 15.1) were employed for all design-based analyses.

We computed weighted estimates of the percentages of young adults (ages 19–23) either in college or not in college having specific past-year SUDs. Adjusted odds ratios, which compared the odds of having a specific SUD between these two subgroups of young adults (after adjusting for covariates, including age, sex, race/ethnicity, nativity, marital status, sexual orientation, urbanicity, geographical region, family income) were then computed with design-based logistic regression models, fitted using pseudo-maximum likelihood estimation to incorporate the weights and complex sampling features. We then examined unadjusted and adjusted associations between sociodemographic covariates and indicators of lifetime psychiatric disorders and the odds of having any past-year DSM-5 SUD, separately for male and female young adults. Finally, we considered subpopulations with specific prior-to-past-year SUDs, and compared them on educational status at the time of the NESARC-III in terms of past-year substance use status measures (no use, past-year non-disordered use, past-year disordered use).

3. Results

3.1. Prevalence of DSM-5 SUDs

Prevalence of any past-year DSM-5 SUD was 39.6% among college students and 44.5% among non-college peers (see Table 1). Adjusted odds of any past-year DSM-5 SUD did not significantly differ as a function of educational status when controlling for sociodemographic covariates. Similarly, the percentage of past-year DSM-5 AUD was 30.7% among college students relative to 27.4% of non-college peers and the adjusted odds did not differ significantly. We examined past-year DSM-5 AUD severity (i.e., mild, moderate, and severe) and found, among those with past-year AUD, no differences in severity between college versus non-college young adults (results not shown). After adjusting for sociodemographic covariates, the prevalence and adjusted odds for past-year DSM-5 tobacco use disorder (AOR=0.50, 95% CI=0.40–0.63) and past-year multiple DSM-5 SUDs (AOR=0.72, 95% CI=0.54–0.95) were significantly lower among college students than non-college peers.

Table 1.

Weighted Prevalence Estimates of Past-Year DSM-5 SUDs among U.S. Young Adults (aged 19-23) by Educational Status (Source: 2012-2013 NESARC-III).

Past-year SUDs	2012–13 NESARC-III In college/school (n = 2,057)	2012–13 NESARC-III Not in college/school (n = 1,213)	AOR (95% CI)a (Sample size)
Any substance use disorderb	39.6%	44.5%	NS
Substance-specific use disorders
Alcohol use disorder	30.7%	27.4%	NS
Tobacco use disorder	17.3%	30.4%	0.50 (0.40–0.63) N = 3,253
Cannabis use disorder	8.6%	9.0%	NS
Cocaine use disorder	0.5%	1.3%	NS
Heroin use disorder	0.3%	0.8%	NS
Hallucinogen use disorder	0.2%	0.3%	NS
Inhalant use disorder	0.1%	0.1%	NS
Rx opioid use disorder	0.9%	1.5%	NS
Rx sedative/tranquilizer use disorder	0.6%	0.9%	NS
Rx stimulant use disorder	0.6%	1.0%	NS
Club/other drug use disorder	0.5%	1.0%	NS
Multiple SUDsc	14.1%	18.9%	0.72 (0.54–0.95) N = 3,253
Illicit drug use disorderd	9.0%	9.6%	NS
Prescription drug use disordere	1.7%	2.5%	NS
Any non-tobacco substance use disorderf	33.9%	31.4%	NS
Multiple non-tobacco SUDsg	6.9%	7.4%	NS

^aAdjusted for age, sex, race, nativity, marital status, sexual orientation, urbanicity, geographical region, and family income (see Table 2 for exact codes).

^bAny substance use disorder is any past-year tobacco, alcohol, cannabis, cocaine, heroin, hallucinogen, inhalant, Rx opioid, Rx sedative/tranquilizer, Rx stimulant, or club/other drug use disorder.

^cMultiple SUDs is two or more past-year disorders: tobacco, alcohol, cannabis, cocaine, heroin, hallucinogen, inhalant, Rx opioid, Rx sedative/tranquilizer, Rx stimulant, or club/other drug use disorder.

^dIllicit drug use disorder is any past-year cannabis, cocaine, heroin, hallucinogen, inhalant, or club/other drug use disorder.

^ePrescription drug use disorder is Rx stimulant, Rx opioid or Rx sedative/tranquilizer use disorder.

^fAny non-tobacco substance use disorder is any past-year alcohol, cannabis, cocaine, heroin, hallucinogen, inhalant, Rx opioid, Rx sedative/tranquilizer, or Rx stimulant, or club/other drug use disorder.

^gMultiple non-tobacco SUDs is two or more past-year disorders: alcohol, cannabis, cocaine, heroin, hallucinogen, inhalant, Rx opioid, Rx sedative/tranquilizer, Rx stimulant, or club/other drug use disorder.

3.2. Sociodemographic and Psychiatric Correlates of DSM-5 SUDs

There were significant associations between demographic characteristics, psychiatric disorders and any past-year DSM-5 SUD among young adult men and women (see Table 2). Young adult women identifying as lesbian had significantly higher rates of SUDs than heterosexual peers, while no such differences were found among young adult men. There were significant associations between selected psychiatric disorders and any past-year SUD among young adult men and women. Approximately 73.1% of young adult men and 61.1% of young adult women with a lifetime personality disorder also had at least one past-year SUD, and percentages were significantly higher than those without these disorders, even after adjusting for all of the variables examined in Table 2.

Table 2.

Weighted Prevalence Estimates of Demographic Characteristics and Psychiatric Disorders Associated with Any Past-Year DSM-5 Substance Use Disorder^a among U.S. Young Adults by Sex (Source: NESARC-III).

Sociodemographic characteristics and psychiatric disorders	Men (n=1,516) % with any SUDa	Men (n=1,508) AOR (95% CI)b	Women (n=1,754) % with any SUDa	Women (n=1,745) AOR (95% CI)b
Age
19 (ref)	39.8	--	30.3	--
20	45.8	1.2 (0.8–1.9)	42.7	1.6 (0.9–2.6)
21	43.7	1.2 (0.8–1.8)	34.3	1.2 (0.8–1.8)
22	51.9	1.7 (1.2–2.4)**	40.6	1.7 (1.0–2.7)*
23	47.3	1.3 (0.9–1.9)	35.5	1.4 (0.8–2.2)
Educational status
In college/school (ref)	43.5	--	35.9	--
Not in college/school	49.9	1.1 (0.8–1.5)	38.7	1.1 (0.8–1.5)
Sexual orientation			***
Heterosexual (ref)	45.5	--	34.6	--
Gay or lesbian	54.7	1.1 (0.6–2.0)	60.7	2.7 (1.3–5.4)**
Bisexual	61.7	1.0 (0.3–3.0)	56.6	1.6 (0.8–2.9)
Not sure	29.3	0.5 (0.1–2.0)	57.4	1.5 (0.4–5.3)
Race/ethnicity	***		***
White (ref)	52.0	--	41.7	--
African-American	36.0	0.6 (0.4–0.8)**	28.5	0.6 (0.4–0.8)**
Other	55.2	1.1 (0.4–3.0)	54.6	1.6 (0.8–3.1)
Asian	27.7	0.5 (0.3–1.0)*	32.6	1.0 (0.6–1.8)
Hispanic	40.6	0.8 (0.6–1.2)	28.2	0.6 (0.4–0.9)**
Marital status			*
Married (ref)	47.6	--	26.2	--
Not married/other	45.7	1.2 (0.7–2.1)	38.1	1.8 (1.0–3.2)*
Geographical region
Northeast (ref)	45.7	--	39.9	--
North Central	51.3	1.2 (0.8–1.7)	38.7	1.0 (0.6–1.5)
South	43.3	0.9 (0.7–1.3)	35.2	1.0 (0.7–1.4)
West	44.4	1.0 (0.7–1.4)	35.3	0.9 (0.6–1.4)
Nativity	***		***
US born (ref)	48.2	--	38.7	--
Non-US born	28.7	0.5 (0.4–0.8)**	20.9	0.5 (0.3–0.9)
Urbanicity	**
Urban (ref)	43.7	--	37.1	--
Rural	57.4	1.4 (0.9–2.1)	35.1	0.8 (0.5–1.4)
Family income (quartiles)
Below $20,000 (ref)	47.0	--	39.2	--
$20,000 - $34,999	45.2	1.0 (0.7–1.4)	36.9	1.2 (0.9–1.7)
$35,000 - $69,999	41.7	0.8 (0.6–1.1)	35.1	1.0 (0.7–1.5)
$70,000 or higher	48.8	1.0 (0.7–1.4)	32.4	0.9 (0.6–1.5)
Anxiety disorder	**		***
No (ref)	43.9	--	32.4	--
Yes	60.0	1.0 (0.7–1.6)	52.0	1.5 (1.1–2.1)**
Mood disorder	***		***
No (ref)	41.3	--	32.1	--
Yes	65.6	1.6 (1.1–2.3)*	47.6	1.0 (0.7–1.4)
Personality disorder	***		***
No (ref)	39.7	--	30.5	--
Yes	73.1	3.3 (2.3–4.6)***	61.1	2.7 (1.9–3.7)***
Eating disorder	**		***
No (ref)	45.5	--	35.5	--
Yes	83.6	2.0 (0.5–8.0)	75.5	3.4 (1.6–7.3)**

^aAny substance use disorder is one past-year tobacco, alcohol, cannabis, cocaine, heroin, hallucinogen, inhalant, Rx opioid, Rx sedative/tranquilizer, Rx stimulant, or club/other drug use disorder.

^bAdjusted for age, educational status, sexual orientation (unknown values of sexual orientation were treated as missing), race/ethnicity, nativity, marital status, urbanicity, geographical region, family income, anxiety disorder, mood disorder, personality disorder, and eating disorder. Sample sizes varied from bivariate Rao-Scott tests of association due to missing data.

ref = reference group.

^*p < 0.05,

^**p < 0.01,

^***p < 0.001, based on Rao-Scott tests of association / design-based Wald tests (for AORs)

3.3. Prevalence of Remission from DSM-5 SUDs

Among young adults with any prior-to-past-year (lifetime) SUDs, the prevalence of past-year abstinent remission was very low among college students (1.0%) and non-college peers (1.9%) (see Table 3). Among young adults with any DSM-5 SUDs, college students were significantly more likely than non-college peers to have continued disordered substance use not involving tobacco, as indicated by a Rao-Scott test (70.2% vs. 60.8%, p=.02). Among young adults with a prior AUD, the prevalence of past-year abstinent remission was very low among college students (1.5%) and non-college peers (3.5%). These two groups did not vary significantly in terms of aggregate past-year substance use status or aggregate past-year substance use status without tobacco. Similar results were found for prior-to-past-year AUDs, tobacco use disorders and multiple prior-to-past-year SUDs (see Supplementary Tables A, B, C, and D).

Table 3.

Weighted Prevalence Estimates of Past-Year Substance Use among U.S. Young Adults with Prior-to-Past-Year Substance Use Disorder(s) by Educational Status (Source: 2012-2013 NESARC-III).

Past-year substance use	2012–13 NESARC Prior-to-past-year substance use disorder(s)a for young adults in college/school (n = 513)	2012–13 NESARC Prior-to-past-year substance use disorder(s)a for young adults not in college/school (n = 376)
Substance useb	P = 0.3023
Past-year substance abstinence	1.0% (n = 9)	1.9% (n = 9)
Past-year non-disordered substance use	17.1% (n = 94)	14.1% (n = 57)
Past-year disordered use	81.9% (n = 410)	84.0% (n = 310)
Non-tobacco substance use	P = 0.0221
Past-year substance abstinence	2.1% (n = 16)	5.1% (n = 25)
Past-year non-disordered substance use	27.7% (n = 150)	34.1% (n = 128)
Past-year disordered use	70.2% (n = 347)	60.8% (n = 223)

^aPrior-to-past-year substance use disorder(s) is one or more prior-to-past-year substance use disorder(s): alcohol, tobacco, cannabis, cocaine, heroin, hallucinogen, inhalant, Rx opioid, Rx sedative/tranquilizer, Rx stimulant, or club/other drug use disorder(s).

^bSubstance use is use of at least one substance in the past 12 months: alcohol, tobacco, cannabis, cocaine, heroin, hallucinogen, inhalant, Rx opioid, Rx sedative/tranquilizer, Rx stimulant, or club/other drug.

Notes: Weighted estimates.

We examined the prevalence of young adults who sought substance use treatment by educational status (see Table 4). We found that the majority of young adults with any lifetime or past-year SUDs had not obtained treatment, regardless of educational attainment. Among U.S. college students with past-year SUDs (n=716), only 12.9% had obtained alcohol or other drug treatment. There were no significant associations in the estimates of treatment between U.S. young adults as a function of educational status.

Table 4.

Weighted Prevalence Estimates of Alcohol and Other Drug Treatment among U.S. Young Adults with Any Prior-to-Past-Year or Past-Year SUDs by Educational Status (Source: 2012–2013 NESARC-III)

	2012–13 NESARC Past-year substance use disorder(s)a for young adults in college/school (n = 761) %	2012–13 NESARC Past-year substance use disorder(s)a for young adults not in college/school (n = 490) %	2012–13 NESARC Prior-to-past-year substance use disorder(s)a for young adults in college/school (n = 511) %	2012–13 NESARC Prior-to-past-year substance use disorder(s)a for young adults not in college/school (n = 375) %
No alcohol or other drug treatment	56.1	62.5 (NS)	63.2	64.3 (NS)
Alcohol treatment only	5.4	3.4 (NS)	7.7	5.1 (NS)
Drug treatment only	4.4	5.3 (NS)	5.7	7.2 (NS)
Alcohol and other drug treatment	1.1	1.7 (NS)	1.7	2.1 (NS)
Alcohol or other drug treatment (any TX)	12.9	10.7 (NS)	17.6	14.9 (NS)

Note: There were no significant association in the estimates between columns 2 vs. 3 nor columns 4 vs. 5.

4. Comments

This is the first study to examine the prevalence, remission and treatment associated with past-year DSM-5 SUD among young adults. An estimated two in every five young adults had a past-year DSM-5 SUD. There were no statistical differences in overall estimates of any SUD, AUD prevalence, or AUD severity based on educational status. Among those with any prior non-tobacco SUDs, the prevalence of past-year abstinent remission was extremely low among college students (1%) and non-college peers (2%). These findings provide evidence that abstinent remission from DSM-5 SUDs is extremely rare among young adults. Despite having free access to support and referral services, 1% of college students achieved sustained abstinent remission from SUDs. These findings support the importance of having a wide range of prevention and treatment approaches when working with college students.²¹

In one past study, college students were significantly less likely to have DSM-IV nicotine dependence than non-college peers (14.6% vs. 20.7%).⁴ The present study extended these findings and estimated that 17.3% of young adults in college had a past-year DSM-5 tobacco use disorder. Notably, past-year tobacco use disorder was more prevalent among non-college young adults (30.4%). The vast majority of past-year DSM-5 tobacco use disorder is driven by cigarette smoking, which is responsible for more than 480,000 deaths per year in the U.S.²² Although further research is needed to better understand risk and protective factors associated with tobacco use by non-college young adults,²³ the impact of policies and laws designating smoke-free college campuses has potentially reduced the prevalence of tobacco use disorder in college students.^24,25

The present study revealed that 14.1% of college students and 18.9% of non-college peers had multiple SUDs. Previous studies stress the need to distinguish multiple SUDs from individual SUDs because the adverse consequences differ between the two.^2,26,27 These findings reinforce the notion that the substance use field should move beyond a substance-specific approach towards diagnosing, studying and treating SUDs to one that takes into account comorbidity of SUDs.⁸ Little research has focused on the adverse effects of individual or multiple SUDs occurring in college populations. Some studies have found an increased likelihood of academic problems, attrition, and comorbid psychopathology among college students diagnosed with an SUD.^28–32 Further research is needed to identify the short- and long-term adverse consequences associated with individual and multiple SUDs in the college population.

The findings of the present study identified correlates associated with past-year SUDs. For example, young adult lesbian-identified women had significantly higher rates of SUDs than heterosexual-identified peers. There is a growing body of research indicating that sexual minority young adults are at heightened risk of SUDs.^33–35 Consistent with prior research regarding comorbidity, the majority of young adults with past-year SUDs had an anxiety, mood and/or personality disorder.^1,2,9 Findings from the present study should be considered within a larger context. Increasingly, college students have reported diagnosis/treatment of psychiatric conditions such as anxiety, panic attacks, and ADHD.³⁶ High rates of comorbidity, coupled with increases in self-reported diagnosis/treatment of psychiatric disorders, may contribute to the high rates of these disorders treated by college health services.³⁷ Thus, it is critical that college campuses continue to provide accessible psychiatric resources to students and should consider implementation of recovery programs for SUDs.¹³

Although more resources are available for college students, they do not seem to be accessing them.³⁸ The present study found that the majority of young adults with multiple SUDs do not receive substance use treatment services, regardless of educational status. This finding is particularly important, and is consistent with other recent national rates that indicate high levels of treatment need and low rates of treatment received among young adults.^14,17 Future research should focus on barriers to treatment among college populations. Colleges and universities are encouraged to assess prevalence of substance use and SUDs on their own campuses rather than relying on national estimates to plan prevention and intervention efforts.

4.1. Limitations

There were study limitations. The NESARC-III was cross-sectional and causal inferences could not be determined. Prevalence estimates of SUDs were likely underestimated because small but high-risk groups of currently institutionalized individuals, such as incarcerated adults, were not included.³⁹ Small samples sizes limited a detailed examination of high-risk subpopulations (e.g., Native American young adults), especially when disaggregating by sociodemographic characteristics. As this was a subsample from a national sample of U.S. noninstitutionalized adults, information about college/university attendance was limited to educational status and details such as type of institution (2- or 4-year) and living arrangement (on-campus, off-campus) were not assessed. Due to the use of self-report, the NESARC data may be biased by recall and report bias.

4.2. Conclusions

Rates of most SUDs did not differ based on college enrollment, and were relatively high in college and non-college young adults. Past-year abstinent remission was extremely low with only 1% of college students and 2% of non-college peers in past-year abstinent remission. This suggests greater efforts are needed to promote abstinence and adequately support college-age young adults in recovery from SUD while accounting for the reality of persistent/recurrent substance use in SUD treatment modalities.