Insomnia and Mental Health in College Students

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1 Behavioral Sleep Medicine ISSN: (Print) (Online) Journal homepage: Insomnia and Mental Health in College Students Daniel J. Taylor, Christie E. Gardner, Adam D. Bramoweth, Jacob M. Williams, Brandy M. Roane, Emily A. Grieser & Jolyn I. Tatum To cite this article: Daniel J. Taylor, Christie E. Gardner, Adam D. Bramoweth, Jacob M. Williams, Brandy M. Roane, Emily A. Grieser & Jolyn I. Tatum (2011) Insomnia and Mental Health in College Students, Behavioral Sleep Medicine, 9:2, , DOI: / To link to this article: Published online: 11 Apr Submit your article to this journal Article views: 6571 View related articles Citing articles: 22 View citing articles Full Terms & Conditions of access and use can be found at

2 Behavioral Sleep Medicine, 9: , 2011 Copyright Taylor & Francis Group, LLC ISSN: print/ online DOI: / Insomnia and Mental Health in College Students Daniel J. Taylor Department of Psychology University of North Texas Christie E. Gardner Department of Psychology Texas Tech University Adam D. Bramoweth Department of Psychology University of North Texas Jacob M. Williams Department of Clinical and Health Psychology University of Florida Brandy M. Roane, Emily A. Grieser, and Jolyn I. Tatum Department of Psychology University of North Texas Insomnia is strongly associated with certain mental health problems in the general population. However, there is little research examining this relation in young adults an age group where many mental health problems first present. This study examined relations between insomnia and mental health symptoms in a college population (N D 373; 60.9% women; mean age of 21 years). Insomnia was assessed via self-report and sleep diaries, and mental health was assessed via the Symptom Check List 90. Analyses revealed insomnia was prevalent (9.4%), and these young adults had significantly more mental health problems than those without insomnia, although some significant results were lost after controlling for comorbid health problems. Young adults are at greater risk than other age groups for developing first onset psychopathology, which may lead to lower social and academic performance and worse long-term outcomes, Correspondence should be addressed to Daniel J. Taylor, Department of Psychology, University of North Texas, P.O. Box , Denton, TX djtaylor@unt.edu 107

3 108 TAYLOR ET AL. such as dropout and underemployment (Christie, Burke, Regier, & Rae, 1988; Kessler, Chiu, Demler, Merikangas, & Walters, 2005). Therefore, it is important to discover what modifiable risk factors are associated with psychopathology in young adults, in hopes of developing prevention programs to decrease the onset of psychopathology, and hopefully prevent the negative secondary outcomes. Insomnia is a diagnostic criterion for many psychiatric disorders (see the Diagnostic and Statistical Manual of Mental Disorders [4th ed., text rev.]; American Psychiatric Association, 2000), so it should not be surprising that many individuals with mental disorders also report insomnia (Breslau, Roth, Rosenthal, & Andreski, 1996; Ford & Kamerow, 1989; Johnson, Roth, & Breslau, 2006; Ohayon, Caulet, & Lemoine, 1998; Ohayon & Roth, 2003; Taylor, Lichstein, & Durrence, 2003; Taylor, Lichstein, Durrence, Riedel, & Bush, 2005). Conversely, as many as 19% to 74.4% of people with insomnia symptoms (PWIS) report mental health problems, depending on the strictness of diagnostic criteria for insomnia and mental health problems (Breslau et al., 1996; Ohayon & Roth, 2003; Sarsour, Morin, Foley, Kalsekar, & Walsh, 2010; Taylor et al., 2005). Unfortunately, it is difficult to determine the true strength of these relations because most studies to date have (a) focused on adults with concomitant health problems, which could be causing or aggravating the insomnia and mental health problems; (b) used variable definitions of insomnia; and (c) generally failed to assess a range of mental health symptomatology beyond just anxiety, depression, or substance abuse. College students are an ideal population to examine insomnia and mental health relationships. College students are also generally physically healthy and represent the majority of the young adult population, as 68% of high school graduates go on to college (U.S. Census Bureau, 2005). As many as 16% to 23% of young adults report insomnia symptoms (Bixler, Vgontzas, Lin, Vela-Bueno, & Kales, 2002; Cukrowicz et al., 2006; Hardison, Neimeyer, & Lichstein, 2005; Karacan et al., 1976), which is comparable to the prevalence in the general population (i.e., 9% 15%; Ohayon & Roth, 2003). Indeed, 7% to 20% of people report their insomnia symptoms started before age 20, and another 11.4% report their symptoms started when they were 21 to 30 years old (Bixler, Kales, Soldatos, Kales, & Healey, 1979; Kales et al., 1984). Despite the high prevalence of insomnia in the young adult population, the disorder is an underrecognized problem in this group (Buboltz, Brown, & Soper, 2001; Hardison et al., 2005). This might explain why the relationship between sleep and mental health in young adults has been understudied. One of the first studies to examine the relationship between insomnia symptoms and psychiatric disorders in young adults (N D 457) found that 12.9% of this population reported continued insomnia (i.e., lasting at least 2 weeks ), which was cross-sectionally related to higher levels of major depression, generalized anxiety, panic, and phobias (Vollrath, Wicki, & Angst, 1989). A more recent study of 1,007 health maintenance organization (HMO) members in Michigan found that in the 21- to 25-year-old participants (n D 375), 16.3% endorsed a lifetime history of at least 2 weeks of trouble falling asleep, staying asleep, or waking up too early nearly every day (Breslau et al., 1996). Those with insomnia symptoms were significantly more likely to have depression, anxiety disorders, and substance abuse or dependence at baseline than those without a lifetime history of insomnia symptoms. The insomnia symptom group was also more likely to develop new depressions, anxiety disorders, and substance abuses or dependences by a 3.5-year follow up. The most recent study in this area looked at the

4 INSOMNIA AND MENTAL HEALTH 109 cross-sectional relationship between both nightmares and insomnia with depression and suicidal behaviors in young adults (N D 222) who were not seeking treatment (Cukrowicz et al., 2006). Both insomnia and nightmares were significantly related to depression, but only nightmares were related to suicidality. These previous studies of relating insomnia symptoms and mental health used varying degrees of specificity in defining insomnia: from an affirmative answer to a lifetime history of insomnia symptoms, to a cutoff score on a symptom questionnaire, which introduces considerable variance and makes it more difficult to compare results to more recent studies that use more specific research or quantitative diagnostic criteria for insomnia (Edinger et al., 2004; Lichstein, Durrence, Taylor, Bush, & Riedel, 2003). Further, they often focused only on specific disorders (e.g., depression and suicidality), which limits our breadth of knowledge. Thus, data reported to date are likely not our best indicators of the true strength of the relationship between insomnia and a wide range of mental health symptomatology. This study examines the relationship between insomnia symptoms and a range of mental health symptoms in young adults, controlling confounding comorbid health problems. Based on previous research, it was hypothesized that PWIS in this age group would have higher levels of mental health symptomatology than people without insomnia symptoms (PWOIS). Participants METHOD College undergraduate students (N D 373; 60.9% women; mean age of 21 years) at a large Southwestern university were recruited during the Spring 2006 semester. The sample s ethnicity was 66.2% Caucasian, 15.3% African American, 9.1% Hispanic, 6.7% Asian American, and 2.7% did not report ethnicity. Most of the classes students were recruited from were part of the university s core curriculum; thus, a large variety of majors were represented psychology (30%); health sciences, math, and engineering (18.5%); visual and performing arts (9.7%); business and management (9.7%); undeclared, general studies, or Texas Academy of Math and Science students (9.7%); language, journalism, English, and communication studies (6.7%); political science and criminal justice (6.2%); education, history, philosophy, and radio, TV, and film studies (4.8%); and other social sciences (4.3%). Procedure Data collection took place during the Spring 2006 semester. Recruitment occurred through a combination of in-class recruitment and distribution of questionnaire packets, classroom announcements, advertisements posted on campus, and an online listing through the department of psychology s research participant pool. In-class recruitment and distribution of questionnaire packets occurred in a psychology course that required participation in research studies. Classroom announcements were made in all psychology courses that offered extra credit for participating in research studies. All students in psychology courses that offered extra credit had access to the research participant pool. Class announcements and flyers directed interested

5 110 TAYLOR ET AL. students to the research participant pool Web site, where they could sign up for the study. After signing up for the study online, participants downloaded and printed the consent form and questionnaires sleep diary, health questionnaire, and the Symptom Check List 90 (SCL 90; Derogatis, Lipman, & Covi, 1973). Once participants completed all parts of the survey, they returned the materials to our research lab. Extra credit points were awarded after the return of the study materials. Eight hundred sixty-six students were signed up for the department of psychology s research participant pool in the Spring 2006 semester. Of those students, 385 signed up for this study (44.5% response rate), and 320 returned their sleep diary and questionnaire (83.1% return rate). Two hundred twenty-two students were given questionnaire packets in class, and 56 returned a sleep diary and questionnaire (25.2% return rate). After excluding participants for not completing the packet sufficiently, the final sample size was 373. The University of North Texas institutional review board on human subjects approved all methodology, and informed consent was obtained from all participants prior to participation. All statistical analyses were performed using SPSS 17 for Windows (IBM Corporation, Somers, NY). Measures SCL 90. Mental health symptoms were assessed with the SCL 90 (Derogatis et al., 1973). The SCL 90 is a 90-item self-report test in which participants indicate how much distress each item has caused over the past week using a Likert-type scale ranging from 0 (not at all) to 4 (extremely). The SCL 90 is an uncopyrighted version of the SCL 90 Revised (SCL 90 R; Derogatis, 1994), explaining why it was used in this large, unfunded survey study. Differences between the SCL 90 and SCL 90 R are minimal, consisting of slight alterations of a few items and the addition of two items in the anxiety domain. Answers are categorized into nine symptom dimensions: somatization, obsessive-compulsive, interpersonal sensitivity, depression, anxiety, hostility, phobic anxiety, paranoid ideation, and psychoticism (for a summary of domains, see Derogatis et al., 1973). The Global Severity Index (GSI) gives the average score of the 90 items (Derogatis et al., 1973). The SCL 90 has high sensitivity and specificity as a screening instrument for global psychological distress and various psychiatric disorders (Derogatis et al., 1973). The SCL 90 domains have an internal consistency reliability range from 0.77 for psychoticism to 0.90 for depression. It has been validated with the Minnesota Multiphasic Personality Inventory (MMPI; Hathaway & McKinley, 1983) scales and shows high criterion validity with each of the corresponding dimensions of the MMPI, except for the obsessive compulsive dimension, which has no comparable scale on the MMPI (Derogatis et al., 1976). As would be expected from basically identical measures, the SCL 90 has similar reliability and validity data as the slightly modified SCL 90 R, indicating that the results reported here should generalize to results that may be found with the newer, copyrighted version. Health questionnaire. Three questions from a health questionnaire, which we designed, were used to establish the operational definition of insomnia (see the following section on the definition of insomnia) in concert with a 1-week sleep diary, using recommendations from sleep epidemiology researchers (Lichstein, Durrence, Riedel, Taylor, & Bush, 2004). In addition,

6 INSOMNIA AND MENTAL HEALTH 111 participants could endorse current sleep complaints from a yes no checklist, including heavy snoring, gasping for breath during sleep, teeth grinding, sleep talking, sleep walking, sleep eating, periodic limb movements, restless legs, sleep attacks during the day, sleep paralysis at sleep onset or upon awakening, and morning headaches. Additional questions from the health questionnaire not used for this study s analyses included questions regarding chronic health, health care utilization, exercise, and substance use. Sleep diaries. One-week sleep diaries were used to prospectively assess subjective sleep patterns. Participants were asked to complete diaries each morning for 7 days. The diaries asked participants to give an estimate of their sleep the night before (e.g., bedtime, sleep onset latency [SOL], wake after sleep onset [WASO], etc.). Definition of Insomnia Symptoms One-week sleep diaries were used to operationally define insomnia, in combination with the following questions from the health questionnaire: 1. Do you have a sleep problem? (Yes/No). 2. If yes, describe (e.g., trouble falling asleep, long or frequent awakenings, sleep apnea). 3. How long have you had this sleep problem? yrs mo. Descriptions of sleep problems were coded as insomnia based on keywords such as trouble falling asleep and frequent awakenings. PWIS was operationally defined as responding yes to having a sleep problem with a description of insomnia symptoms for at least 6 months (i.e., chronic), with an insomnia sleep pattern defined as 31 min SOL or WASO, or a combination 3 times per week using the sleep diary. This insomnia symptoms definition is common throughout the literature and has been empirically validated (Lichstein et al., 2003). The added daytime complaint component was excluded from this definition for a variety of reasons that are rarely discussed in the insomnia literature. First, it was impossible to examine differences between groups (i.e., insomnia vs. no insomnia) on a dependent variable (i.e., mental health symptoms) without causing circularity because the dependent variable (i.e., mental health symptoms as a daytime complaint) was used to define the groups. Second, even if only non-mental health daytime complaints (e.g., fatigue) were used, this would necessarily leave out a substantial group of people whose primary daytime complaint was mental health difficulties (i.e., one of the most common daytime complaints of people with insomnia). One solution to this problem would be to ask a more general question of, To what extent do you consider your sleep problem to interfere with your daily functioning? ; but, unfortunately, this study did not do such an assessment; and, even if it had, it would be impossible to say if the participants were reporting on mental health symptoms or not. One final point on this matter is that, in the past, researchers often used as indicators of daytime dysfunction elevated scores on common measures of mental health, fatigue, quality of life, and so forth that do not specifically reference insomnia as the causal factor. It should be clear that this is not an accurate or appropriate assessment of the daytime component, since the participant never says their daytime dysfunction is a result of their insomnia.

7 112 TAYLOR ET AL. Missing Data RESULTS In this study, missing data was minimal. No data was missing for dependent variables (SCL 90 subscales), and missing data for independent variables ranged from 0.5% to 4.6% of the sample. According to Tabachnick and Fidell (2007), when only a few data points are missing (i.e., <5%) and the sample size is large, the majority of missing data procedures (e.g., deleting cases, mean substitution, or multiple imputation) produce similar results. Since only a small percentage of the data from this sample was missing, we used pairwise exclusion (i.e., participants with missing data were excluded from analyses with no data imputation) to handle the missing data, which Tabachnick and Fidell deemed appropriate. Analytic Plan The overall goals of this study were to estimate the prevalence of insomnia symptoms in college students, followed by an examination of the relation of insomnia symptoms with mental health problems in this sample. In the first analysis, simple descriptive statistics were performed to determine what portion of our sample reported significant insomnia symptoms using the previously mentioned operational definition. Next, in an attempt to determine if those in our sample reporting insomnia symptoms also had greater levels of mental health symptoms, we performed independent samples t tests, with insomnia status as the grouping variable and mental health symptoms, as measured by scores on the SCL 90 subscales, as the dependent variables. These group comparisons were then repeated, controlling medical comorbidity, to ensure results were not confounded. Insomnia Symptoms Prevalence Using the insomnia symptom definition described earlier, 9.4% of our sample was labeled as PWIS and 58.2% as PWOIS. We excluded individuals from subsequent analyses if they had (a) a complaint of chronic insomnia, but not the insomnia sleep pattern (13.4%); (b) no complaint of chronic insomnia, but had the insomnia sleep pattern (12.9%); or (c) had another sleep disorders (6.2%), such as sleep apnea or periodic limb movements. Insomnia Symptoms and Mental Health Symptoms Because the homogeneity of variance assumption was violated for all SCL 90 scales, the following results assume unequal variance between PWIS and PWOIS. Also, to control for multiple comparisons, the alpha level was set at p < :01. As can be seen in Table 1 (see also Figure 1), PWIS scored significantly higher than PWOIS on somatization, obsessivecompulsive, depression, anxiety, and psychic distress (all ps < :01). It is of note that two of the items on the SCL 90 deal with sleep (Items 44 and 66). These two items are only used to calculate GSI; therefore, to avoid any circularity, they were removed from GSI analyses and remained highly significant.p D :003/.

8 INSOMNIA AND MENTAL HEALTH 113 TABLE 1 T Scores, Means, Standard Deviations, and Independent t Tests of People With Insomnia Symptoms (PWIS) Versus People Without Insomnia Symptoms (PWOIS) on Symptom Check List 90 Dimensions PWIS (n D 35) PWOIS (n D 217) Total (N D 373) PWIS vs. PWOIS a Variable T M SD T M SD M SD t p Somatization <.001 Obsessive compulsive Interpersonal sensitivity Depression Anxiety Hostility Phobic anxiety Paranoid ideation Psychoticism Global Severity Index a Equal variances not assumed. As mentioned, previous studies have been confounded by the inclusion of participants with significant medical disorders, which could be causing both the insomnia and mental health symptomatology. In this study, 30.6% of participants reported at least one medical problem (e.g., cancer D 0.8%, hypertension D 1.6%, neurological D 0.8%, breathing [e.g., asthma] D 9.9%, urinary D 3.6%, diabetes D 0.4%, pain D 6.7%, gastrointestinal D 6.0%, immune D 1.2%, sexually transmitted disease D 2.4%, and migraines D 11.1%). A chi-square test of independence found that 57.1% of PWIS had at least one medical disorder, as opposed to 24.9% of PWOIS, 2.1; N D 252/ D 15:12, p < :001. To demonstrate the confound that medical disorders can play in examining the relation between insomnia and mental health problems, a second set of t tests were run, excluding those with medical disorders from the FIGURE 1 Symptom Check List 90 (SCL 90) scores in people with insomnia (PWI) symptoms versus people without insomnia (PWOI) symptoms (all ps < :05).

9 114 TAYLOR ET AL. analysis. This method was chosen over analysis of covariance because the heterogeneity of variance assumption was violated between groups. After removing those with any reported medical disorder, functionally reducing power (i.e., PWIS D 15 and PWOIS D 163), the only remaining difference at the p < :01 alpha level was for obsessive-compulsive symptoms, with PWIS reporting greater symptoms (M D 1:46, SD D 0:84) than PWOIS (M D 0:87, SD D 0:63), t.176/ D 3:40, p D :001. However, there continued to be differences at the p < :05 alpha level for somatization, depression, anxiety, GSI, and GSI without sleep items. DISCUSSION This study found that chronic insomnia symptoms are common in college students (9.4%), and that PWIS self-reported higher levels of somatization, obsessive compulsive, depression, anxiety symptomatology, and psychic distress (i.e., GSI) even after removing the two sleep items than PWOIS. However, when comorbid medical problems were taken into account, only obsessive compulsive symptom differences remained. The prevalence data are somewhat lower than prevalence data from other studies of young adult populations (Bixler et al., 1979; Cukrowicz et al., 2006; Hardison et al., 2005; Karacan et al., 1976), which is to be expected considering the use of a more rigorous definition in this study (e.g., Ohayon & Roth, 2003). The differences seen between PWIS and PWOIS were in agreement with those of previous studies (Breslau et al., 1996; Cukrowicz et al., 2006; Vollrath et al., 1989), although this study gives a more accurate assessment of the strength and breadth of this relationship within young adults by using a more rigorous definition of insomnia and a more comprehensive measure of mental health symptomatology. The SCL 90 scores of PWIS, although elevated, were lower than all of those found in psychiatric outpatients from the original normative studies (Derogatis, 1994), except somatization, where PWIS had a mean raw score of 0.91 and the psychiatric sample was 0.87, which appears to be a negligible difference. The PWOIS of this sample were within the same range as the adolescent non-patients in the original study (Derogatis, 1994). Differences between groups on subscales should be interpreted with caution. Some researchers question the dimensionality of the SCL 90 (Clark & Friedman, 1983; Cyr, McKenna-Foley, & Peacock, 1985), and suggest it be used mainly as a one-dimensional measure of psychological distress, which is supported by the significant correlations found between all scales on the SCL 90 in this study. Although it is unknown if the insomnia symptoms resulted in increased mental health symptomatology or if mental health symptomatology led to insomnia symptoms in college students, it is clear that this is a problem for the college population, as well as the general population. This is the first study to examine insomnia symptoms and mental health symptomatology in the college student population specifically, and this study also examined a much larger array of mental health symptomatology than previous studies and used a more rigorous definition of insomnia symptoms. Further, this study shows support for the idea that previous studies were flawed by their failure to control for comorbid medical disorders. When that was done in this study, some significant results were lost, although this may have been an artifact of reduced power more than incorrect results. One methodological limitation of our study was that it only assessed the relation of insomnia symptoms and mental health symptomatology cross-sectionally. Thus, it is difficult to determine

10 INSOMNIA AND MENTAL HEALTH 115 if insomnia symptoms are a precursor to or consequence of the mental health problems. In the future, researchers need to assess the relationship between insomnia symptoms and mental health longitudinally to address the progression of this relationship. This would allow for a more definitive association between insomnia symptoms and mental health symptomatology by identifying factors that lead to the development, progression, and remission of the two disorders (National Institutes of Health, 2005). Longitudinal studies would also aid in the development of primary, secondary, and tertiary prevention interventions, therefore reducing the onset and consequences of insomnia symptoms and other mental health problems in the young adults. Another limitation of this study was that mental health and insomnia symptoms were only assessed with self-report measures. This is less than optimal because self-report tends to be somewhat inaccurate. However, the cost of standardized clinical interviews to assess these domains often makes their use untenable in all but the best-funded epidemiology studies. Further, it is not clear how much additional data they can provide because, as mentioned, most self-report measures of insomnia symptoms and psychopathology have been validated against standardized clinical interviews. However, future studies might consider structured clinical interviews for both insomnia symptoms and mental health problems and perhaps use objective measurements of sleep (e.g., actigraphy). As mentioned throughout, the young adult age group is particularly susceptible to the onset of major psychiatric disorders. This study shows that the significant relationship between insomnia symptoms and mental health found in the general population holds true in the college population as well. Other studies are now needed examining the prospective nature of this relationship to determine if insomnia symptoms are a modifiable risk factor for the onset or maintenance of mental health problems. If so, the next logical step would be to develop primary and secondary prevention programs, which might attenuate some of the more salient consequences (i.e., dropout) for this age group, which can possibly result in employment difficulties, lower socioeconomic statuses, and so forth in the future. REFERENCES American Psychiatric Association. (2000). Diagnostic and statistical manual of mental disorders (4th ed., text rev.). Washington, DC: Author. Bixler, E. O., Kales, A., Soldatos, C. R., Kales, J. D., & Healey, S. (1979). Prevalence of sleep disorders in the Los Angeles metropolitan area. Americal Journal of Psychiatry, 136, Bixler, E. O., Vgontzas, A. N., Lin, H. M., Vela-Bueno, A., & Kales, A. (2002). Insomnia in central Pennsylvania. Journal of Psychosomatic Research, 53, Breslau, N., Roth, T., Rosenthal, L., & Andreski, P. (1996). Sleep disturbance and psychiatric disorders: A longitudinal epidemiological study of young adults. Biological Psychiatry, 39, Buboltz, W. C., Jr., Brown, F., & Soper, B. (2001). Sleep habits and patterns of college students: A preliminary study. Journal of American College Health, 50, Christie, K. A., Burke, J. D., Regier, D. A., & Rae, D. S. (1988). Epidemiologic evidence for early onset of mental disorders and higher risk of drug abuse in young adults. American Journal of Psychiatry, 145, Clark, A., & Friedman, M. J. (1983). Factor structure and discriminant validity of the SCL 90 in a veteran psychiatric population. Journal of Personality Assessment, 47, Cukrowicz, K. C., Otamendi, A., Pinto, J. V., Bernert, R. A., Krakow, B., & Joiner, T. E., Jr. (2006). The impact of insomnia and sleep disturbances on depression and suicidality. Dreaming, 16, Cyr, J. J., McKenna-Foley, J. M., & Peacock, E. (1985). Factor structure of the SCL 90 R: Is there one? Journal of Personality Assessment, 49,

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