The Effects of Sleep Quality on Theory of Mind

Transcription

1 Butler University Digital Butler University Undergraduate Honors Thesis Collection Undergraduate Scholarship 2016 The Effects of Sleep Quality on Theory of Mind Julie Erwin Butler University, jerwin@butler.edu Follow this and additional works at: Part of the Clinical Psychology Commons Recommended Citation Erwin, Julie, "The Effects of Sleep Quality on Theory of Mind" (2016). Undergraduate Honors Thesis Collection This Thesis is brought to you for free and open access by the Undergraduate Scholarship at Digital Butler University. It has been accepted for inclusion in Undergraduate Honors Thesis Collection by an authorized administrator of Digital Butler University. For more information, please contact omacisaa@butler.edu.

2 SLEEP QUALITY AND THEORY OF MIND 1

3 SLEEP QUALITY AND THEORY OF MIND 2 The Effects of Sleep Quality on Theory of Mind A Thesis Presented to the Department of Psychology College of Liberal Arts and Sciences and The Honors Program of Butler University In Partial Fulfillment of the Requirements for Graduation Honors Julie Erwin April 6 th, 2016

4 SLEEP QUALITY AND THEORY OF MIND 3 Thesis Description Previous research indicates a relationship between Theory of Mind (ToM; the ability to discern others thoughts, emotions, intentions, etc.) and psychological disorders. Further, previous research has described a relationship between psychological disorders and sleep disruption. However, no existing research has examined whether sleep quality is associated with ToM. In this study, I explored that relationship in a healthy undergraduate population. To address this question, I proposed to correlate measures of ToM with measures of sleep quality. Background As sleep disorders have become prevalent among Americans, issues of cognitive processes have been a topic of concern. According to the DSM-5, one-third of Americans report symptoms of insomnia and 40-50% of those with insomnia also present a comorbid mental disorder (American Psychiatric Association, 2013). Increasingly, researchers have implicated sleep disruption in creating compromised mood functioning, cognitive abilities, and metacognition, providing results that differ significantly from a healthy population (Harvey, Schmidt, Scarna, Semler, & Goodwin, 2005). Discovering whether or not characteristics of sleep and perceived levels of restfulness have an effect on Theory of Mind the ability to perceive thoughts and emotions in other people can help us understand if higher quality or duration of sleep is necessary to more accurately perceive emotions and expressions. Previous research has determined a relationship between sleep disruption and cognitive dysfunction. Cognitive abilities that have commonly been affected by sleep disruption are attention, concentration, memory, mood regulation, and response time.

5 SLEEP QUALITY AND THEORY OF MIND 4 Previous research has shown that those with higher levels of sleep disruption display lower density of REM sleep (Zanini, et. al. 2013). Quality of sleep has also been related to cognitive processes in such a way that those with less REM sleep have been shown to have higher levels of depression and lower levels of accuracy in testing (Diaz, et. al. 2013). Those with sleep deprivation often struggle to maintain attention on tasks regardless of difficulty (Martella, et. al., 2013). Sleep deprivation has been found to interfere with one s response time to certain tasks in comparison to non-sleep deprived individuals, resulting in a slower response time in sleep deprived individuals (van Enkhuizen, Halberstadt, Zhuang & Young, 2013). Memory has been found to be compromised in sleep deprived individuals in comparison to a healthy population (Corrêa, et. al. 2013). While ample evidence exists to implicate sleep disruptions in compromised cognitive capabilities, little evidence currently exists connecting sleep disruption to compromised metacognitive abilities. One potentially illuminating case of a psychological disorder that has well-established connection to sleep disruption, compromised cognitive functioning, and impaired metacognition is bipolar disorder. According to the DSM-5, individuals with bipolar disorder experience alternating periods of extreme elation and extreme sadness (American Psychiatric Association, 2013). Disruptions in circadian rhythms in individuals with bipolar disorder are common; during manic episodes, individuals with bipolar disorder sleep very little, and in depressive episodes hypersomnia occurs. Perhaps more telling, individuals with bipolar disorder who are between episodes (i.e., during periods when mood is comparatively normal) were significantly more likely than

6 SLEEP QUALITY AND THEORY OF MIND 5 individuals with primary insomnia (without bipolar disorder) to have clinically disturbed sleep (Harvey, Schmidt, Scarna, Semler, & Goodwin, 2005). Interestingly, in addition to demonstrating sleep problems, individuals with bipolar disorder have also demonstrated impairments in cognitive abilities. Multiple studies have found that individuals with bipolar disorder also suffer from disruptions in cognitive abilities such as memory, learning and attention (Corrêa, et. al., 2013; Wright, Lipszyc, Dupuis, Thayaparajah, Schachar, 2014). Previous research has shown that memory is impaired among individuals suffering from bipolar disorder. Those with bipolar disorder commonly have impaired episodic memory compared to a healthy population (Czepielewski, et. al., 2015). It has also been found that those with bipolar disorder have deficits in attention (Wright, et. al., 2014). In addition to compromised cognitive abilities, studies have also found evidence of compromised metacognitive abilities such as Theory of Mind among individuals with bipolar disorder. For example, Rossell and Van Rheenen (2012) studied groups of bipolar and healthy individuals using a story comprehension task, which measures indirect or sarcastic communication. They found that individuals with bipolar disorder scored significantly more poorly on the story comprehension task than the healthy control group. In another study done by Kerr, Dunbar & Bentall (2003), bipolar and healthy individuals completed a story task on false beliefs and deception. It was found that individuals with bipolar disorder scored significantly more poorly on the Theory of Mind task than the healthy individuals within the study. Therefore, there is significant evidence that Theory of Mind is affected in individuals with bipolar disorder.

7 SLEEP QUALITY AND THEORY OF MIND 6 Due to the relationship between bipolar disorder and sleep disruption and bipolar disorder and Theory of Mind, it is suspected that sleep disruption is linked to Theory of Mind impairment. While there is some indication that sleep increases the ability to draw inferences, (Ellenbogen, Hu, Payne, Titone, Walker, 2007), a critical component of ToM, there is no current research evaluating whether sleep disruption interferes with ToM. Discovering whether or not characteristics of sleep and perceived levels of restfulness have an effect on Theory of Mind can help us understand if quality or duration of sleep is necessary to accurately perceive emotions and expressions. It is also important to note that discovering whether or not sleep deprivation impacts Theory of Mind will aid in the understanding of disorders that are closely related to compromised sleep. In this study, it is hypothesized that Theory of Mind and sleep will correlate with one another. Based on previous research, it is suspected that individuals suffering from poor sleep quality will have compromised Theory of Mind. Method Participants In this study, 45 participants from a college population were recruited from psychology classes and were offered extra credit in accordance with their class policy. Participant characteristics are reported in Table 1.

8 SLEEP QUALITY AND THEORY OF MIND 7 Table 1. Demographic characteristics of the sample (n=45). Gender Age Race Year in School GPA 35 Female 10 Male (M=20.4, s.d.=1.2) 43 White 1 Black 1 Other 4 First Year 9 Sophomore 12 Junior 19 Senior 1 Other (M=3.49, s.d.=.39) Materials The Hinting Task (see Appendix), originally developed by Corcoran, Mercer, & Frith (1995) and adapted for North American use by Greig, Bryson, & Bell (2004), is a commonly used Theory-of-Mind measure (Bora et. al., 2009) and requires participants to make inferences about someone s intended meaning. The Hinting task measures the social-cognitive domain of ToM (Tager-Flusberg & Sullivan, 2000). The Hinting task consists of 10 brief vignettes describing interactions between two characters where one character provides a hint to the other character. Participants hear each vignette and are asked by the experimenter what the main character really means. A correct answer at this point receives a score of 2. If the participant offers an answer other than the correct one, the experimenter offers a second prompt and a correct answer receives a score of 1. An incorrect response receives a score of 0. Scores on the vignettes result in one total score ranging from 0-20.

9 SLEEP QUALITY AND THEORY OF MIND 8 The Story Comprehension task (SCT; see Appendix) analyzes the perception of sarcasm or ironic communication (Langdon & Coltheart, 2004). This measure is comprised of 96 brief (2-3 sentence) vignettes where the participant is asked to indicate whether one of the characters in the vignette says "something that a person might say in that situation." "Yes" responses may be either sarcastic, a figure of speech, or literally appropriate, while "no" responses are nonsensical or irrelevant to the given situation. The number of correct responses are summed to yield a total score and scores on each of the dimensions (sarcastic, figure of speech, literal, nonsense). The Reading the Mind in the Eyes Test (Eyes; Baron-Cohen, Wheelwright, Hill, Raste, & Plumb, 2001; see Appendix) is one of the most widely used Theory of Mind measures (Bora, Yucel, & Pantelis, 2009) and requires participants to decode complex mental states in others. Consisting of 36 photos, cropped to include only a person s eyes, the Eyes Test measures the social-perceptual domain of ToM (Tager-Flusberg & Sullivan, 2000). Participants are asked to choose from four adjectives surrounding each photo the one that best describes the mental state of the individual in the photo. Participants answers are coded either correct (1) or incorrect (0), yielding a possible range of 0-36 as a total score. Internal State Scale (ISS; Bauer et al., 1991; see Appendix) is a frequently-used self-report measure of bipolar symptoms. Comprised of 15 Likert scales ranging from 0-100, the ISS yields 4 subscale scores: Activation, Well-Being, Perceived Conflict, and Depressive symptoms. It is included in the present study because of the well-described relationship between bipolar symptoms and ToM, as well as the relationship between bipolar symptoms and sleep.

10 SLEEP QUALITY AND THEORY OF MIND 9 Center for Epidemiologic Studies Depression inventory (CES-D; Radloff, 1977; see Appendix). The CES-D is a well-validated and widely used measure of depressive symptoms. It is a 20 item self-report measure with each Likert scale ranging from 0-3, yielding a possible range of It is particularly useful for identifying a range of depressive symptoms in non-clinical samples. It is included in the present study because depressive symptoms are commonly correlated with ToM. The Pittsburgh Sleep Quality Index (PSQI; Buysse, Reynolds III, Monk, Berman, & Kupfer, 1989; see Appendix) is a commonly used measure in sleep studies to assess self-reported, subjective characteristics of sleep. Participants are assessed on their experiences with sleep within the past month. These experiences are divided into 7 subscales: subjective sleep quality, sleep latency (how long it takes to fall asleep), sleep duration, habitual sleep efficiency (the percentage of time spent in bed actually asleep), sleep disturbances, use of sleep medication, and daytime dysfunction. These subscales are then summed to create a global score. Procedures After providing informed consent, participants completed the ToM tasks (Hinting, Eyes, & SCT), and then were asked to complete the PSQI and the demographic questionnaire (see Appendix). At the close of each session, participants were thanked for their time and any concerns were addressed. Results Preliminary analyses. Demographic characteristics of the sample were examined to assess for potential covariates. Because the design included multiple dependent variables, I conducted a series of correlation analyses and t-tests to examine the effects of

11 SLEEP QUALITY AND THEORY OF MIND 10 demographic and symptom variables on the DVs. A number of significant relationships were discovered, which are displayed in Table 2. Subsequently, the variables that affect each DV will be entered as covariates. Table 2. Significant relationships between demographic/symptom covariates and Theory of Mind measures. ToM Measure Covariate Statistic Significance Eyes GPA r =.381 p =.010 Hinting Year in School r =.326 p =.029 SCT Total Gender t (43) = 2.02 p =.036 SCT Sarcasm Gender t (43) = 2.24 p =.030 SCT Sarcasm CES-D r =.325 p =.029 NOTE: Eyes = Reading-the-mind-in-the-eyes; SCT = Story Comprehension Task. For the SCT Total score, females (M=82.28) were significantly more capable than males (M=76.5). For the SCT Sarcasm score, females (M=11.31) were significantly more capable than males (M=8.70). Main analyses. The present study included a single IV (sleep quality) and a multifaceted dependent variable (Theory of Mind), all of which are continuous variables. Therefore, the first pass analyses used a series of multiple regression analyses, each analysis using overall sleep quality as the primary IV and each ToM measure as separate DVs. For regressions where covariation was necessary (see preliminary analyses) the covariate was entered first into the model and then sleep quality was entered in the second step. Thus, seven separate regressions were performed in the first pass: PSQI Global as the primary IV for each analysis and Hinting, Eyes, SCT Total, SCT Literal, SCT Figure of Speech, SCT Sarcasm, and SCT Nonsense as DVs. Following the first pass analyses, a second pass was made where, instead of the PSQI Global as the IV, the seven PSQI subscales

12 SLEEP QUALITY AND THEORY OF MIND 11 were used as IVs using the SPSS command, stepwise (again after entering necessary covariates in the first step). Thus, seven additional regressions were performed in the second pass: PSQI subscales as stepwise IVs for each analysis, and Hinting, Eyes, SCT Total, SCT Literal, SCT Figure of Speech, SCT Sarcasm, and SCT Nonsense as DVs. A significant relationship emerged between overall sleep quality (as measured by the PSQI Global score) and the Nonsense Subscale of the SCT, F (1, 43) = 4.237, p =.046, β = -.299, R 2 =.090. This relationship is depicted in Figure 1 and suggests that as sleep gets worse, a person s ability to identify nonsense communication becomes progressively more impaired. No other significant relationships emerged (all p >.05).

13 SLEEP QUALITY AND THEORY OF MIND 12 Figure 1. Relationship between Overall Sleep Quality and Theory of Mind as measured by the Story Comprension Task s Nonsense subscale. To expand on the above results, I compared the best-sleeping 1/3 of the sample (individuals with PSQI global scores 4; n = 18) to the worst-sleeping 1/3 of the sample (individuals with PSQI global scores 7; n = 13) on the Story Comprehension Test variables. Consistent with the previous analyses, covariates were considered when they related to the particular DV. Also consistent with previous analyses, sleep quality did not affect the SCT Total score nor the Literal, Figure of Speech, or Sarcasm subscales (all p s >.25). However, the effect for the Nonsense subscale was replicated: the best-sleeping 1/3 of the sample (M = 43.72, s.d. = 3.49) significantly outperformed the worst-sleeping

14 SLEEP QUALITY AND THEORY OF MIND 13 1/3 of the sample (M = 38.77, s.d. = 6.69), F (1, 29) = 7.22, p =.012, η 2 =.199. Thus, even with the reduced statistical power that comes with reduced sample size and segmenting a continuous variable, the deleterious effects of poor sleep quality on the ability to identify nonsense communication remained apparent. Discussion The present study examined the relationship between sleep quality and Theory of Mind. I hypothesized that individuals suffering from poor sleep quality would also suffer compromised ToM. Results offer limited support for this hypothesis. While most measures of ToM were not related to sleep quality, one subscale of one measure the Nonsense subscale of the Story Comprehension Task evidenced a significant relationship to sleep quality. This result suggests that individuals who sleep more poorly have an impaired ability to detect nonsense or non-sequiturs in conversation. The potential connection between poor sleep quality and story comprehension illuminates several questions on what sleep quality may have to do with finding meaning in what an individual says. One potential explanation is that sleep deprivation tends to make individuals more vulnerable to threatening stimuli (Prather, Bogdan, & Hariri, 2013); therefore they may be more sensitive to what an individual says by finding meaning when there is no meaning at all. If this is the case, individuals who have worse sleep quality may have a harder time determining nonsense from sense information. The present results suggest that poorly-sleeping individuals may be more likely to make sense out of nonsensical information perhaps because they are on high alert for threat.

15 SLEEP QUALITY AND THEORY OF MIND 14 A number of limitations are apparent in the present study, such as the sample demographics. Most of the participants were college-aged Caucasian female students, which is not representative of the general population. Age, gender, and race are limited within this study, which does not allow us to see how various age groups, races, and males respond to Theory of Mind measures as well as their report on sleep quality data. It is possible that younger or older individuals might report differing levels of sleep quality and Theory of Mind ability, thus providing that our sample may only represent a college population. Had my study been more diverse in race, it could reveal racial differences in sleep quality and Theory of Mind data. However, the vast majority of participants were Caucasian (43 out of 45; 95.6%); thus my results may only represent the Caucasians. As the participants were primarily female, this made it exceptionally difficult to compare scores between males and females to see if there were any gender differences within the sample. While participant gender did affect some ToM measures, the imbalance in the sample and the lack of any previous research suggesting gender effects on ToM prevent me from drawing any firm conclusions about this observation. Overall, these limitations affect the generalizability of this study to the population at large. As there has been no evidence of demographic differences affecting Theory of Mind in previous research; this may not be a particular concern The present sample was also particularly well rested, suggesting that our sample was limited by only being able to analyze a specific range of sleep quality. For example, the average response to the question, during the past month, how would you rate your overall sleep quality, was between Very good and fairly good. Similarly, the average PSQI Global score was 5.6 (s.d. = 2.73); the range of possible PSQI scores is

16 SLEEP QUALITY AND THEORY OF MIND 15 between 0 (no difficulty) and 21 (severe difficulties in all areas). This is a limitation because we are not able to see how variability in sleep quality relates to Theory of Mind data and if there is a potential relationship between higher and lower levels of sleep quality in comparison to the range reported by the sample. Another limitation of the current study would be the use of multiple tests, increasing the probability of making a Type I error. Although I used multiple statistical tests to evaluate the hypotheses, thus artificially inflating the experiment-wise alpha, this was deliberate. Because of the novelty of the hypothesis, I wanted to be sure that I would not miss a potentially interesting relationship. Similarly, the use of stepwise regressions increases the probability of Type I error. Again, this was a deliberate attempt to catch any interesting relationships. Because of the small sample size of the present study and the resultant limited statistical power, the ability to detect truly existing differences was already compromised. For these reasons, I believe the liberal criteria for detecting differences was justified. Future research on this topic should further investigate the potential implications of sleep quality on Theory of Mind by investigating a large and diverse sample where a more accurate picture of the general population may be pictured. If there is a broad range of sleep quality to study, this would uncover potential relationships between sleep quality and Theory of Mind. It would also be important to look at a sample with a larger age range, as this would be more generalizable to the population and could diminish some of the potential effects of a college population on sleep or Theory of Mind ability. As the sample of this study was mainly comprised of females, further research should include a more gender-balanced study to ensure no effects of gender are implied. Future research

17 SLEEP QUALITY AND THEORY OF MIND 16 should also focus specifically on sleep deprived individuals to see if there are implications with sleep deprivation on Theory of Mind. This could be contrasted to a well-rested sample, such as the one provided by this study.

18 SLEEP QUALITY AND THEORY OF MIND 17 References American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Washington, DC: Author. Backhaus, J., Junghanns, K., Broocks, A., Riemann, D., & Hohagen, F. Test retest reliability and validity of the Pittsburgh Sleep Quality Index in primary insomnia. Journal of Psychosomatic Research, 53(3), Baglioni, C., Regen, W., Teghen, A., Spiegelhalder, K., Feige, B., Nissen, C., & Riemann, D. (2014). Sleep changes in the disorder of insomnia: A meta-analysis of polysomnographic studies. Sleep Medicine Reviews, 18(3), Baron-Cohen, S., Wheelwright, S., Hill, J., Raste, Y., & Plumb, I. (2001). The "Reading The Mind In The Eyes" Test Revised Version: A Study With Normal Adults, And Adults With Asperger Syndrome Or High-functioning Autism. Journal of Child Psychology and Psychiatry, 42(2), Bauer, M.S., Crits-Christoph, P., Ball, W.A., Dewees, E., McAllister, T., Alahi, P., Cacciola, J., & Whybrow, P.C. (1991). Independent assessment of manic and depressive symptoms by self-rating: Scale characteristics and implications for the study of mania. Archives of General Psychiatry, 48, Buysse, D., Reynolds III, C., Monk, T., Berman, S., & Kupfer, D. (1989). The Pittsburgh Sleep Quality Index: A New Instrument For Psychiatric Practice And Research. Psychiatry Research, 28(2) Corrêa, M. S., da Silveira, E. S., de Lima, D. B., Balardin, J. B., Walz, J. C., Kapczinski, F., & Bromberg, E. (2015). The role of encoding strategies in contextual memory deficits in patients with bipolar disorder. Neuropsychological Rehabilitation, 25(1), Cote, K. (2013). Impact of total sleep deprivation on behavioural neural processing of emotionally expressive faces. Experimental Brain Research, 232(5), Cricco, M., Simonsick, E., & Foley, D. (2001) The Impact of Insomnia on Cognitive Functioning in Older Adults. Journal of the American Geriatrics Society, 49(9), Czepielewski, L., Massuda, R., Goi, P., Sulzbach-Viana, M., Reckziegel, R., Costanzi, M., Kapczinski, F., Rosa, A.R., & Gama, C. (2015). Verbal episodic memory along the course of schizophrenia and bipolar disorder: A new perspective. European Neuropsychopharmacology, 25(2), Diaz, B. A., Sluis, S. V., Moens, S., Benjamins, J. S., Migliorati, F., Stoffers, D.,... Linkenkaer-Hansen, K. (2013). The Amsterdam Resting-State Questionnaire

19 SLEEP QUALITY AND THEORY OF MIND 18 reveals multiple phenotypes of resting-state cognition. Frontiers in Human Neuroscience Front. Hum. Neurosci., 7. Ellenbogen, J. M., Hu, P. T., Payne, J. D., Titone, D., & Walker, M. P. (2007). Human relational memory requires time and sleep. Proceedings of the National Academy of Sciences, 104(18), Enkhuizen, J., Geyer, M., Halberstadt, A., Zhuang, X., & Young, J. (2014). Dopamine depletion attenuates some behavioral abnormalities in a hyperdopaminergic mouse model of bipolar disorder. Journal of Affective Disorders, 155, Harvey, A.G., Schmidt, D. A., Scarna, A., Semler, N. C., & Goodwin, G. M., (2005). Sleep-Related Functioning in Euthymic Patients With Bipolar Disorder, Patients With Insomnia, and Subjects Without Sleep Problems. American Journal of Psychiatry, 162(1), Kerr, N. (2003) Theory of mind deficits in bipolar affective disorder. Journal of Affective Disorders, 73(3), Langdon, R., Coltheart, M., (2004). Recognition of metaphor and irony in young adults: the impact of schizotypal personality traits. Psychiatry Research, 125(1), Martella, D., Marotta, A., Fuentes, L., & Casagrande, M. (2014). Inhibition of Return, but Not Facilitation, Disappears Under Vigilance Decrease Due to Sleep Deprivation. Experimental Psychology, 61(2), Prather, A. A., Bogdan, R., &. Hariri, A.R.. (2013). Impact of Sleep Quality on Amygdala Reactivity, Negative Affect, and Perceived Stress. Psychosomatic Medicine, 75(4), Radloff, L. S. (1977). The CES-D scale: A self report depression scale for research in the general population. Applied Psychological Measurements, 1, Rheenen, T., & Rossell, S. (2013). Picture sequencing task performance indicates theory of mind deficit in bipolar disorder. Journal of Affective Disorders, 151(3) Rossell, S., & Rheenen, T. (2013) Theory of mind performance using a story comprehension task in bipolar mania compared to schizophrenia and healthy controls. Cognitive Neuropsychiatry, 18(5) Wright, L., Lipszyc, J., Dupuis, A., Thayapararajah, S. W., & Schachar, R. (2014). Response inhibition and psychopathology: A meta-analysis of go/no-go task performance. Journal of Abnormal Psychology, 123(2).

20 SLEEP QUALITY AND THEORY OF MIND 19 Zanini, M., Castro, J., Coelho, F., Bittencourt, L., Bressan, R., Tufik, S., & Brietzke, E. (2013) Do sleep abnormalities and misaligned sleep/circadian rhythm patterns represent early clinical characteristics for developing psychosis in high risk populations? Neuroscience & Biobehavioral Reviews, 37(10),

21 SLEEP QUALITY AND THEORY OF MIND 20 Appendix The Hinting Task

22 SLEEP QUALITY AND THEORY OF MIND 21 Reading the Mind in the Eyes Task

23 SLEEP QUALITY AND THEORY OF MIND 22 Story Comprehension Task

24 SLEEP QUALITY AND THEORY OF MIND 23 Internal State Scale

25 SLEEP QUALITY AND THEORY OF MIND 24 Center for Epidemiologic Studies Depression

26 SLEEP QUALITY AND THEORY OF MIND 25 Pittsburgh Sleep Quality Index INSTRUCTIONS: The following questions relate to your usual sleep habits during the past month only. Your answers should indicate the most accurate reply for the majority of days and nights in the past month. 1. During the past month, what time have you usually gone to bed at night? : am / pm 2. During the past month, how long (in minutes) has it usually taken you to fall asleep each night? 3. During the past month, what time have you usually gotten up in the morning? : am / pm 4. During the past month, how many hours of actual sleep did you get at night? (this may be different than the number of hours you spent in bed) For each of the remaining questions, please mark the one best response. 5. During the past month, how often have you had trouble sleeping because you Not during the past month Less than once a week Once or twice a week Three or more times a week a. Cannot get to sleep within 30 minutes? O O O O b. Wake up in the middle of the night or early morning? O O O O c. Have to get up to use the bathroom? O O O O d. Cannot breathe comfortably? O O O O e. Cough or snore loudly? O O O O f. Feel too cold? O O O O g. Feel too hot? O O O O h. Had bad dreams? O O O O i. Have pain? O O O O j. Other - specify: O O O O 6. During the past month, how would you rate your sleep quality overall? Very Good Fairly Good Fairly Bad Very Bad 7. During the past month, how often have you taken medicine to help you sleep (prescribed or "over the counter")? Not during the past month Less than once a week Once or twice a week Three or more times a week

27 SLEEP QUALITY AND THEORY OF MIND During the past month, how often have you had trouble staying awake while driving, eating meals, or engaging in social activity? Not during the past month Less than once a week Once or twice a week Three or more times a week 9. During the past month, how much of a problem has it been for you to keep up enough enthusiasm to get things done? No problem at all Only a very slight problem Somewhat of a problem A very big problem

28 SLEEP QUALITY AND THEORY OF MIND 27 Demographic