Sleep Medicine 12 (2011) 598–602
Contents lists available at ScienceDirect
Sleep Medicine
journal homepage: www.elsevier.com/locate/sleep
Original Article
Sleep quality and characteristics of college students who use prescription
psychostimulants nonmedically
Megan M. Clegg-Kraynok b,1, Amanda L. McBean a, Hawley E. Montgomery-Downs a,⇑
a
b
West Virginia University, Department of Psychology, 53 Campus Dr., P.O. Box 6040, Morgantown, WV 26506-6040, United States
Formerly at West Virginia University, Department of Psychology, United States
a r t i c l e
i n f o
Article history:
Received 24 May 2010
Received in revised form 14 January 2011
Accepted 21 January 2011
Keywords:
Prescription
Psychostimulant
Sleep quality
Emerging adult
Characteristics
Nonmedical use
a b s t r a c t
Objective: Although psychostimulants have been shown to affect sleep in experimental studies, the relation between nonmedical psychostimulant use and sleep has not been examined. Our goal was to
describe the sleep quality and characteristics of college students who use psychostimulant medications
nonmedically.
Methods: We surveyed 492 college students about their sleep quality and psychostimulant use characteristics. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI); psychostimulant use
and characteristics were measured via a survey developed for this study.
Results: College students who self-reported current or a history of nonmedical psychostimulant use
reported worse subjective sleep quality, sleep disturbance, and global PSQI scores than nonusers. The
most commonly reported reason for nonmedical psychostimulant use was to improve work performance
and concentration.
Conclusions: These data demonstrate worse sleep quality among nonmedical psychostimulant users. The
likely consequence of increased daytime sleepiness helps to confirm the known public health concern of
nonmedical prescription psychostimulant use among college students.
Ó 2011 Elsevier B.V. All rights reserved.
1. Introduction
Adolescence and young adulthood is accompanied by sleep pattern changes that often result in decreased sleep quality and consequent increased daytime sleepiness. Biological changes during
this period include a delayed circadian phase shift causing the tendency to stay up later at night.1–3 Early school start times, extracurricular activities, part-time jobs, and increased freedom to
self-select bedtimes also contribute to poor sleep habits among
adolescents and young adults.3,4 College students report average
weekday sleep durations between 7.0 and 7.2 h5–7 despite requiring about 9 h for optimal functioning.8 Low sleep quality, sleep disturbances, and at least occasional sleep dissatisfaction are
prevalent among most college undergraduates.6,9,10
The college environment provides increased exposure to alcohol and drugs, the use of which may exacerbate sleep problems
among students. Although prescription psychostimulants such as
methylphenidate, dextroamphetamines, and mixed-salt ampheta⇑ Corresponding author. Tel.: +1 304 293 2001x610, fax: +1 304 293 6606.
E-mail address: [email protected] (H.E. MontgomeryDowns).
1
Currently at Ohio Northern University, Department of Psychology and Sociology,
Hill Memorial Building, 525 South Main St. Ada, OH 45810, United States. Tel.: +1 419
772 2135, fax: +1 419 772 2746.
1389-9457/$ - see front matter Ó 2011 Elsevier B.V. All rights reserved.
doi:10.1016/j.sleep.2011.01.012
mines are intended for use among those with attention deficit
hyperactivity disorder (ADHD)11,12 they are also readily available
to those without prescriptions. DeSantis, Webb and Noar found
that nearly 85% of college students reported that it is ‘‘very easy’’
or ‘‘somewhat easy’’ to illegally obtain prescription stimulants,
thus these medications are often used illicitly.13 Prevalence of such
illicit psychostimulant use ranges from 5% to 43% among samples
of college students,14–21 with amphetamine use being most
common.15,22
The most frequently reported route of administration among
nonmedical users is oral administration; nasal administration is
the next most common route and has been reported among
14.7–38.1% of nonmedical users.16,22 When psychostimulants are
crushed and nasally inhaled, the nasal mucosa allows absorption
directly into the bloodstream, increasing bioavailability and abuse
potential due to the nearly immediate reinforcing effects of dopamine release.11 This finding in particular emphasizes the public
health issue of nonmedical psychostimulant use.
Common motives for undergraduate student use of prescription
psychostimulants include increasing alertness and concentration,
improving academic work and performance, staying awake longer
to study or while using other drugs, to ‘‘get high’’, weight control,
and to counteract the effect of other drugs.13,14,23,24 Although college students also report that avoiding sleep is a major motivator
for abusing prescription psychostimulants,23 the relation between
M.M. Clegg-Kraynok et al. / Sleep Medicine 12 (2011) 598–602
sleep quality and nonmedical psychostimulant use has been
understudied.
Thus, the purpose of the current study was to characterize sleep
quality among college students who use prescription psychostimulant medications nonmedically compared to nonusers. We expected nonmedical psychostimulant users to report poorer sleep
quality than nonusers based on a vicious cycle. Namely, sleep deprived individuals prefer psychostimulants,25 and sleep deprived
individuals use psychostimulants to avoid sleep,14,23,24 which further deteriorates sleep, possibly leading to preference for psychostimulants. A secondary study goal was to characterize the
nonmedical users’ sources for obtaining these drugs, routes of
administration, types of prescription psychostimulants used, and
motives for use. Though the secondary characteristics have been
described in previous studies, the current study is the first to address these measures concurrent with sleep quality.
2. Methods
The study was approved by the Office of Research Compliance
(IRB) at West Virginia University. Data collection occurred during
an 8 week period from mid-October through mid-December
2007. Undergraduate students P18 years living in university housing or enrolled in an undergraduate psychology class were invited
to complete the online survey. To maintain anonymity, a cover letter that explained consent was used in place of a signed consent
form. Because these data were anonymous, we are unable to report
response rate. Age and grade point average (GPA) were assessed
categorically so participants could not be retrospectively linked
to their survey responses. Online safeguards were in place to allow
students to participate only once.
To date no survey regarding nonmedical psychostimulant use
has been validated. Our questions regarding use and motives were
based on several previously published studies of college-age samples.14,18,26 Because previous research has found that members of
campus sororities and fraternities are more likely to engage in nonmedical psychostimulant use18, we included this measure in the
demographics section of the survey. In addition, photographs of
each dose of each drug were provided as a visual reference. Participants were categorized as nonmedical lifetime users, prescription
users, or nonusers. Nonmedical lifetime users were operationally
defined as those who answered ‘‘yes’’ to the question, ‘‘Have you
used prescription stimulants for non-medical use?’’ Those who answered ‘‘no’’ to this question, but endorsed use of specific drugs,
which were presented with both generic (e.g., methylphenidate,
mixed-salt amphetamine, dextroamphetamine and modafinil)
and trade names (e.g., Ritalin, Adderall, Dexedrine, DextroStat,
Provigil and Nuvigil) were considered prescription users. This
question, posed after the portion of the survey concerning lifetime
use of psychostimulants, was not elucidated for participants to
permit self-selection as nonusers or nonmedical users. Because
medically approved use was not assessed, prescription users were
excluded from analyses. Only participants who endorsed any lifetime use were asked to complete the final portion of the survey,
with questions concerning duration of use, method of administration, whether they thought it was acceptable to use these drugs,
methods for obtaining the drugs, and motives for drug use.
The Pittsburgh Sleep Quality Index (PSQI)27 was used to assess
sleep quality. The PSQI consists of 19 survey questions related to
sleep habits within the past month including average sleep duration, latency, and specific sleep-related problems such as reasons
you have had trouble sleeping, administration of medications to
help you sleep, and daytime sleepiness. These questions are
grouped to form seven component scores each with a range of 0–
3: sleep quality, sleep latency, sleep duration, sleep efficiency,
599
sleep disturbance, use of sleep medications, and daytime dysfunction. These component scores are then summed for a global sleep
quality score (range 0–21) with higher scores reflecting worse
sleep quality during the previous month. The PSQI demonstrates
good diagnostic sensitivity and specificity.27 Clinical cutoffs of
>527 and P59 for the PSQI have both been used. For this study, global PSQI score P5 was used as the cutoff between good and poor
sleep quality, consistent with a previous study of college-age
students.9
2.1. Sample
Five hundred sixty-six students completed the online survey.
Two participants were excluded because of incomplete data and
72 were excluded because they could not be unequivocally classified as nonmedical users or non-users. Analyses were based on the
final sample of 492 participants.
2.2. Statistical analyses
SPSS version 16.0 was used to analyze data. Descriptive statistics were calculated and categorical comparisons between nonusers and nonmedical users were made using chi-square analyses.
Pairwise deletion was used for any missing data, and Cohen’s d
was used to determine effect sizes for statistically significant group
differences.
3. Results
Among the 492 participants, 14.4% reported lifetime nonmedical psychostimulant use. Table 1 shows that there were differences
between groups for year in school, GPA, fraternity/sorority affiliation, and living arrangement.
Half (50.2%) of all respondents were freshmen. The majority of
nonusers (53.4%) were freshmen, while the majority of nonmedical
users (66.5%) were divided between the freshmen (31.0%) and
sophomores (35.2%). Analyzed separately by class, we found that
8.9% of freshmen respondents reported being nonmedical users,
18.4% of sophomore respondents reported nonmedical use, 23.5%
of junior respondents reported nonmedical use, 15% of senior
respondents reported nonmedical use, and although the sample
of those in their fifth or higher year of college was low (n = 12),
33% reported nonmedical psychostimulant use.
A greater proportion of nonmedical users were in lower GPA
categories than nonusers. Divided by GPA categories, we found
that 5.7% of GPA 3.5–4.0 respondents reported nonmedical use,
15% of GPA 3.0–3.49 respondents reported nonmedical use, 21.6%
of GPA 2.5–2.99 respondents reported nonmedical use, and among
those with GPAs 62.49, 17% reported nonmedical use.
Only 8.8% of the sample (n = 44) was affiliated with a sorority or
fraternity. However, among the sorority or fraternity-affiliated
sample, 31.8% reported nonmedical use, compared to 13.9% of
those without sorority or fraternity affiliation.
Among the whole sample, 95% lived in either a university residence hall or a personal residence. The majority (65.3%) of nonusers lived in residence halls, whereas nonmedical users were
divided between living in residence halls (45.7%) and in a personal
residence (50.7%). Among those who lived in the residence halls,
10% reported being nonmedical users, whereas 22% who lived in
a personal residence reported nonmedical use.
Frequency of nonmedical use of each drug is shown in Table 2.
Among nonmedical users, mixed-salt amphetamine was the most
frequently used drug.
The average global PSQI score for all study participants (6.5
[±2.9]) was above the P5 cutoff for poor sleep quality. To examine
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M.M. Clegg-Kraynok et al. / Sleep Medicine 12 (2011) 598–602
Table 1
Demographic and educational characteristics for lifetime nonmedical users and
nonusers (N = 492).
Ethnicity
Caucasian
African
American
Other
Gender
Female
Male
Age
18–20 years
21–24 years
25 + years
Year in school
Freshman
Sophomore
Junior
Senior
5th year +
GPA
3.5–4.0
3.0–3.49
2.5–2.99
2.0–2.49
Below 2.0
Nonmedical users (n = 71)
Nonusers
(n = 421)
91.5%
2.8%
91.1%
3.6%
5.6%
5.3%
64.8%
35.2%
70.3%
29.7%
77.5%
22.5%
0.0%
85.3%
13.3%
1.4%
31.0%
35.2%
21.1%
7.0%
5.6%
53.4%
26.4%
11.6%
6.7%
1.9%
9.9%
46.5%
36.6%
5.6%
1.4%
27.6%
44.4%
22.4%
4.9%
0.7%
0.12
0.87
4.99
**
Nonusers
Subjective sleep quality
Sleep latency
Sleep duration
Habitual sleep efficiency
Sleep disturbance
Use of sleep medications
Daytime dysfunction
Global PSQI
0.25
1.35
1.14
0.51
1.23
0.35
1.58
6.40
(0.64)
(0.92)
(0.88)
(0.83)
(0.47)
(0.63)
(0.75)
(2.90)
Users
0.62
1.46
1.15
0.55
1.36
0.35
1.66
7.17
(0.85)
(0.86)
(0.86)
(0.73)
(0.51)
(0.68)
(0.77)
(2.85)
df
(1490)
(1490)
(1488)
(1485)
(1489)
(1490)
(1490)
(1489)
F
d
***
18.15
0.89
0.02
0.16
4.26*
0.00
0.68
4.25*
0.49
0.27
0.27
Note: Provided for each group are means (standard deviation) and effect sizes
(Cohen’s d).
*
p < 0.05;
***
p < 0.001.
15.51**
13.02**
Sorority or fraternity
affiliation
No affiliation
Living arrangement
Residence hall
Personal residence
With parents/family
Sorority/fraternity house
***
v2
Table 3
PSQI component scores for lifetime nonmedical users versus nonusers.
Nonmedical users
(n = 77)
Nonusers
(n = 421)
v2
18.3%
7.1%
9.48**
81.7%
92.9%
43.7%
50.7%
1.4%
4.2%
65.3%
29.9%
4.3%
0.5%
22.25***
p < 0 .01.
p < 0 .001.
Table 2
Frequency of psychostimulant use among nonmedical users.
Drug
Never
(%)
Used but not
in past year (%)
Used in past
year (%)
Used in past
month (%)
Methylphenidate
Mixed-salt
amphetamine
Dextroamphetamine
Modafinil
77.5
19.7
7.0
11.3
7.0
18.3
8.5
50.7
93.0
98.6
4.2
0.0
0.0
1.4
2.8
0.0
(scores < 5), 25th–50th percentiles (scores 5–6), 50th–75th percentiles (scores 7–8), and above the 75th percentile (scores > 8). After
controlling for the demographic information, there was neither a
significant main effect for sleep quality (p = 0.59) nor an interaction between nonmedical use and sleep quality (p = 0.90). A significant main effect for nonmedical use on GPA was found (F = 6.86,
p = 0.009).
Among the 71 participants who endorsed nonmedical psychostimulant use, oral administration was reported more frequently
(89.7%) than nasal administration (29.4%), (v2[1] = 18.7,
p < 0.001). There was not a significant difference on global sleep
quality between nonmedical users who reported having ever used
nasal administration versus those who used only oral administration (p = 0.50).
Participants were instructed to mark all applicable motives and
methods of administration. The most frequently endorsed motives
for nonmedical psychostimulant use were to enhance study/work
performance (41.4%), increase concentration (28.6%), to get high
(10.0%), for social reasons (10.0%), to increase alertness (8.6%), curiosity/experimentation (7.1%), counteract other drugs (2.9%), and
other (7.1%). ‘‘Other’’ included ‘‘to relax,’’ ‘‘weight loss,’’ ‘‘to help
me study,’’ ‘‘to get things accomplished around the house,’’ ‘‘for
both concentration and alertness for long drives,’’ and ‘‘makes me
feel more confident and social’’.
Nonmedical users’ methods for obtaining prescription psychostimulants were valid prescription for a friend who gave the drug
to the participant (59.2%), from an acquaintance (39.7%), valid prescription for a friend who sold the drug to the participant (17.6%),
valid prescription for a family member (8.8%), and valid prescriptions for falsified symptoms (1.5%).
4. Discussion
differences between nonmedical users and nonusers’ global and
component PSQI component, a MANOVA was conducted with use
category as the independent variable and PSQI scores as the dependent variables. Demographics variables were not included as
covariates in this analysis. Lifetime nonmedical psychostimulant
users had significantly worse global PSQI scores, and nonmedical
users also had worse component scores for subjective sleep quality
and sleep disturbance (Table 3).
To evaluate the impact of sleep and nonmedical psychostimulant use on academic performance, we ran a factorial ANOVA with
GPA as the dependent variable, and both nonmedical use status
and global sleep quality as independent measures. Demographic
data were entered as covariates into the model (age, gender, year
in college, ethnicity, membership in sororities or fraternities, and
place of residence). Because several missing cells prevented us
from running global sleep quality as a continuous measure, it
was recoded as a categorical variable below the 25th percentile
Nonmedical psychostimulant users reported worse subjective
and overall sleep quality and more sleep disturbance than nonusers. Students reporting high GPAs were least likely to use psychostimulants nonmedically. In fact, the results of this study indicate
that the effect of nonmedical use on GPA is stronger than either
the effect of sleep quality or interaction of nonmedical use and
sleep quality on GPA. This result suggests that research examining
sleep and sleep quality among emerging adults should include
measures of nonmedical psychostimulant use.
The proportion of nonmedical use during each year of college
shows that freshmen and sophomores are the least likely to be
users. These younger students are also more likely to live in a residence hall, which probably explains our findings that students in
residence halls were less likely to be nonmedical users than those
living in personal residences. Perhaps the increased monitoring in
residence halls plays a part in lower rates of nonmedical use
M.M. Clegg-Kraynok et al. / Sleep Medicine 12 (2011) 598–602
among freshmen and sophomores than among upper level students. Additionally, participants reporting the highest GPAs were
least likely to be nonmedical users even though commonly supported motives for use are related to studying and productivity.
These results also support research demonstrating higher rates of
nonmedical use among sorority and fraternity members than
nonmembers.18
Nonmedical psychostimulant use was related to worse subjective sleep quality even after excluding variance due to demographic measures. No differences were found in global sleep
quality based on method of drug administration (nasal versus oral),
nor did we find a main effect of global sleep quality on GPA or an
interaction between nonmedical use and global sleep quality on
GPA. In line with previous research, we determined that most nonmedical users obtained the drugs from friends and acquaintances.16,28 Overall, respondents used mixed-salt amphetamine
and methylphenidate most often. Oral administration of psychostimulant was most common; the proportion of users who reported nasal administration was 27%.
4.1. Nonmedical psychostimulant use and sleep
Despite the average global PSQI score being above the generally
accepted clinical cutoff for this age group9, which is not uncommon9,29, we found that nonmedical users had significantly worse
subjective sleep quality, sleep disturbance, and global sleep quality
than nonusers. Specifically, the component scores in this study
(nonusers mean = 0.92, range = 0.25–1.58; nonmedical users
mean = 1.02, range = 0.35–1.66) were higher than among healthy
control adults in the United States (mean = 0.52, range = 0.20–
0.70),27 Singapore (mean = 0.62, range = 0.02–1.09),30 and Japan
(mean = 0.51, range = 0.39–0.66).31,32 During further investigation
of nonmedical use and sleep with academic performance, we found
no main effect of sleep or interaction effect of use and sleep quality
on GPA. However, we did find a main effect of use status on GPA
suggesting that sleep quality, which is generally poor among college students, is playing a smaller role in academic outcomes than
nonmedical psychostimulant use. Therefore, future studies examining sleep quality among emerging adult use should consider nonmedical psychostimulant use in addition to general demographic
information.
These findings may suggest a pattern of behavior—not necessarily of current nonmedical psychostimulant use, but of poor sleep
among people who have used these drugs. Alternatively, there
may be a general propensity toward nonmedical use of psychostimulants among students at risk for sleep disturbance. Finally,
a cycle of nonmedical psychostimulant use may exist to combat effects of the medications. Specifically, we speculate that decreased
sleep quality from psychostimulant use might prompt further misuse of these drugs. Students report using psychostimulants to reduce need for sleep for a variety of reasons,14 though this study
demonstrates no significant differences in sleep duration among
nonmedical users and nonusers. It is possible that the lack of differences in sleep duration between the groups is due to nonmedical
users developing a tolerance for psychostimulants.11
Though not unexpected, high scores on the PSQI among this
population are of specific concern because lack of sufficient and/
or restorative sleep leads to poor academic performance.32–35
Though no relation between sleep quality and GPA was found, it
is possible that reported GPA for this study does not reflect current
sleep disturbance because the PSQI corresponds to the previous
month and GPAs are calculated based on all previous grades
earned. Moreover, transforming PSQI scores into categorical data
resulted in loss of variance, further inhibiting our ability to confirm
previous findings.
601
4.2. Motives for use and sources for obtaining psychostimulants
Nonmedical psychostimulant users’ report poorer sleep than
nonusers and nonmedical users reported using psychostimulants
to enhance work performance and improve concentration in our
studies and others23,36; these findings support the notion that students’ ultimate goal may be to prevent sleep with these drugs to
improve academic performance.
The current study also extends the current literature by determining that participants predominantly reported obtaining psychostimulants from friends or acquaintances, similar to previous
research.16,28 Thus, not only is nonmedical use facilitated by prescribed users, but prescribed users who need these medications
for a health condition may not be taking their prescription medications. Further, it is unlikely that accurate dosage specifications are
provided to nonmedical users of psychostimulants, increasing risk
of overdosing. Information about the route of obtaining these
drugs may help focus educational programs aimed to reduce nonmedical psychostimulant use.
4.3. Limitations
A major limitation of this study is the lack of random sampling,
resulting in a sample with a large proportion of females, freshmen,
and sophomores, which may not generalize to other university
populations. In addition, the anonymous survey used to encourage
honest responding meant we were unable to track participation
rate. Another major limitation is that information concerning other
stimulants (e.g. nicotine and caffeine) or illicit drugs was not collected, nor were participants screened for ADHD, anxiety, or
depression. Lack of this information limits our ability to attribute
variance in sleep measures exclusively to psychostimulant use
and prevents analyses of psychostimulant use in participants with
preexisting disorders.
Because nonmedical use was not experimentally manipulated,
no cause-effect relations between use and sleep can be determined. The cross sectional design also did not allow evaluation
of the temporal association between nonmedical use and sleep
quality. Furthermore, use of self-report limits the amount and type
of information we can infer about students’ sleep and sleep patterns; though parents and adolescents have sufficiently estimated
sleep characteristics such as bedtimes and wake times, they were
unreliable in predicting sleep onset latency, frequency of night
awakenings, and total sleep time.37,38 It is also possible that nonmedical users believe their sleep quality is worse because their
motive for nonmedical use stimulants is to stay awake longer.
4.4. Future directions
The priority for future research in this area should be the relation between nonmedical psychostimulant use and objective sleep
measured via actigraphy or polysomnography during periods
when nonmedical use is closely monitored. In addition, frequency
of psychostimulant use should be included in future surveys as
well as measures of behavioral and affective disorders in an attempt to examine any influence they may have on nonmedical
use. Finally, future studies could be extended to measure the effect
of medical use of psychostimulants on sleep and sleep quality.
5. Conclusions
Despite these limitations, the current study takes a first step at
bridging an important gap in knowledge between nonmedical psychostimulant use and sleep quality. We hope these results will
encourage use of experimental designs, as well as further field
602
M.M. Clegg-Kraynok et al. / Sleep Medicine 12 (2011) 598–602
assessments, to incorporate objective assessment of these drugs to
further describe the effects of nonmedical psychostimulant use on
sleep and consequences such as drowsy driving and risk behaviors,
mood disturbance, and academic outcomes.
Conflict of interest
The ICMJE Uniform Disclosure Form for Potential Conflicts of
interest associated with this article can be viewed by clicking on
the following link: doi:10.1016/j.sleep.2011.01.012.
Acknowledgements
We thank our study participants and the anonymous journal
reviewers whose comments and suggestions substantially improved our work.
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