- Email: [email protected]
The role of preoccupation in attributions for poor sleep
Sleep Medicine 8 (2007) 277–280 www.elsevier.com/locate/sleep
Brief Communication
The role of preoccupation in attributions for poor sleep Jason Ellis *, Sarah E. Hampson, Mark Cropley Department of Psychology, University of Surrey, Guildford, Surrey GU27XH, UK Received 18 November 2005; received in revised form 14 July 2006; accepted 14 August 2006 Available online 26 March 2007
Abstract Background and purpose: Studies examining the impact of daytime preoccupations with sleep are rare. The aim of the present study was to determine whether daytime preoccupations mediate the relationship between anxiety and attributions for poor sleep within older adults. Method: A cross-sectional study examined the mediational role of sleep preoccupations in the link between anxiety and attributions for poor sleep in a sample of late-life insomniacs (n = 92). Results: The findings show that a preoccupation with sleep during the day mediates the relationship between anxiety and both sleep effort and sleep pattern problem attributions but does not mediate cognitive arousal attributions for insomnia and only partially mediates the relationship between anxiety and physical tension attributions for insomnia. Conclusions: The results are discussed in terms of the existing models of insomnia and cognitive intervention strategies. Ó 2007 Published by Elsevier B.V. Keywords: Sleep preoccupation; Late-life insomnia; Attributions; Cognitive intrusion
1. Introduction A nighttime preoccupation with sleep has long been established as a key factor in preventing sleep-onset [1,2] and in attributions for sleep-onset insomnia [3]. However, there is little evidence on the effects of daytime preoccupations on attributions for poor sleep despite preoccupation and daytime distress being markers of insomnia under both the Diagnostic and Statistical Manual of Mental Disorders – 4th Edition (DSM-IV) [4] and International Classification of Sleep Disorders – 2nd Edition [5]. Interestingly, levels of daytime distress and, more specifically, levels of general anxiety discriminate insomniacs from non-complaining poor sleepers [6], and anxiety has been shown to be a better predictor of the presence of sleep complaints than total sleep time measured polysomnographically [7]. Moreover, the daytime thoughts of insomniacs are more focused on sleep than those of normal *
Corresponding author. Tel.: +44 1483686936; fax: +44 1483879553. E-mail address: [email protected] (J. Ellis).
1389-9457/$ - see front matter Ó 2007 Published by Elsevier B.V. doi:10.1016/j.sleep.2006.08.011
sleepers [8]. As such, the processes under which anxiety and daytime preoccupations interact, leading to attributions for insomnia, requires further attention. In terms of sleep-onset insomnia, one suggested pathway is sleep-related cognitions mediating the relationship between anxiety and attributions for sleep-onset insomnia [3]. Similarly, Harvey’s [9] cognitive model proposes an interaction between negatively toned daytime cognitive activity and distress. The aim of the present study was to determine whether daytime preoccupations mediate the relationship between anxiety and attributions for poor sleep within older adults. The University of Surrey Advisory Committee for Ethics approved the protocol for the study. 2. Method 2.1. Procedure Participants were recruited from an existing sample of late-life insomniacs (see [10] for details). They were
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J. Ellis et al. / Sleep Medicine 8 (2007) 277–280
recruited through a magazine for older adults and were screened for insomnia using a 65-item structured sleep history assessment (see [11] for an example). Recruitment also incorporated the Insomnia Severity Index [12] and DSM-IV criteria for primary insomnia with one exception; certain chronic illnesses were included in the sample to retain ecological validity (e.g., HIV, controlled hypertension). However, those reporting uncontrolled illnesses that affect the central nervous system (e.g., uncontrolled Type 2 diabetes) were excluded because these illnesses directly affect sleep parameters [13]. Additionally, participants had previously been screened, and excluded, for neurological or psychiatric illnesses, other sleep disorders, or major depression (i.e., 611 on the Hospital Anxiety and Depression Scale (HADS)). Participants were contacted a year after the initial study and asked if they would like to take part in a study on daytime factors in insomnia (n = 246). They were sent a booklet containing the original screening/exclusion tools, the Sleep Disturbance Questionnaire (SDQ), HADS, and Sleep Preoccupation Scale (SPS). Of the 246 questionnaires sent, 128 (52.03%) were returned.
the SPS to have a high internal reliability in both student and older adult samples (a = .79 and .82, respectively) and to discriminate late-life insomniacs from normal sleepers [18,19]. In the present study, reliability was (a = .88). 2.4. Participants Of the 128 responses received, 26 participants were eliminated for having high levels of depression (P11 on the depression dimension of the HADS) and 10 participants were eliminated as they no longer met the criteria for insomnia. The final sample consisted of 92, 17 (18.5%) men and 75 (81.5%) women. The mean age of the sample was 70.90 (standard deviation (SD) 8.18) years, and the mean duration of insomnia was 13.20 years (SD 16.53). The mean score for anxiety was 8.85 (SD 2.98) and SPS was 36.55 (SD 11.75). Additionally, the mean SDQ score was 36.48 (SD 9.74) with the following for each dimension; physical tension (M 8.55, SD 2.88), cognitive arousal (M 10.70, SD 3.31), sleep pattern problems (M 9.43, SD 2.71), and sleep effort (M 7.79 SD 2.76). 2.5. Analytic strategy to examine mediation
2.2. Measures 2.2.1. Sleep Disturbance Questionnaire (SDQ) The SDQ [14] consists of 12 statements, scored on a five-point scale, relating to four dimensions: Physical Tension, Cognitive Arousal, Sleep Pattern Problems, and Sleep Effort. It measures causal attributions concerning the perceived source of sleep problems. The test demonstrates good reliability and internal reliabilities on the subscales range from a = 0.59–0.82 [15]. 2.3. Hospital Anxiety and Depression Scale (HADS) The HADS [16] examines depression and anxiety within non-psychiatric populations. It consists of 14 statements (7 relating to anxiety and 7 to depression) to which the respondent chooses one of four responses that best represents how they have felt over the past few weeks. The HADS has been used extensively on a wide variety of health issues, and both dimensions demonstrate a good internal reliability [17]. 2.3.1. Sleep Preoccupation Scale (SPS) The SPS assesses the frequency of sleep-related thoughts, feelings, or behaviors during the day. The SPS contains 20 statements, scored on a seven-point Likert-type scale: ‘1’ = Never to ‘7’ = Always. Scores range between 20 and 140, with higher scores indicating more sleep preoccupation. Items include ‘I cannot stop thinking about the sleep during the day’ and ‘I keep checking to see if I look tired’. Previous pilot-work has shown
To test mediation, three regression analyses were conducted on the total SDQ score and on each dimension. The first regression examined the relationship between predictor (i.e., anxiety) and mediator (i.e., SPS). The second examined the relationship between predictor and dependent variable (i.e., SDQ dimension score) and the final regression, both predictor and mediator on the dependent variable. If mediation exists, anxiety should be a significant predictor of both sleep preoccupation scores in the first regression and SDQ scores in the second regression but not a significant predictor (or significantly reduced, indicating partial mediation) of the SDQ score in the third regression, whereas SPS must be a significant predictor. 3. Results Results from the regression analyses showed that sleep preoccupation mediated the anxiety: the overall attribution relationship and, more specifically, the anxiety-sleep effort relationship and the anxiety-sleep pattern problem relationship. There was a partial mediational role of sleep preoccupation in the anxiety-physical tension relationship but no mediation between the anxiety-cognitive arousal relationship (Table 1). 4. Discussion Sleep preoccupation mediated overall attributions for poor sleep and, specifically, sleep effort and sleep pattern
J. Ellis et al. / Sleep Medicine 8 (2007) 277–280
279
Table 1 Regression analyses testing the mediational role of sleep preoccupation in attributions for late-life insomnia Predictor variable
Outcome variable
R2
R2 change
B
SEB
b
Anxiety
Sleep preoccupation
0.26
0.25
1.99
0.36
0.51***
Anxiety Anxiety + Sleep preoccupation
Total SDQ scores Total SDQ scores
0.20 0.22
0.19 0.21
1.46 0.02 0.11
0.31 0.10 0.03
0.45*** 0.02 0.46***
Anxiety Anxiety + Sleep preoccupation
Physical tension Physical tension
0.15 0.23
0.15 0.21
0.38 0.23 0.08
0.09 0.11 0.03
0.39*** 0.24* 0.31**
Anxiety Anxiety + Sleep preoccupation
Cognitive arousal Cognitive arousal
0.24 0.30
0.24 0.28
0.55 0.40 0.08
0.10 0.11 0.03
0.49*** 0.36*** 0.27*
Anxiety Anxiety + Sleep preoccupation
Sleep pattern problem Sleep pattern problem
0.10 0.19
0.09 0.17
0.29 0.13 0.08
0.09 0.10 0.03
0.32** 0.14 0.35**
Anxiety Anxiety + Sleep preoccupation
Sleep effort Sleep effort
0.07 0.22
0.06 0.21
0.24 0.02 0.11
0.09 0.10 0.03
0.26* 0.02 0.46***
* ** ***
= p < 0.05. = p < 0.005. = p < 0.001.
problem attributions. These findings are consistent with the hypothesized mediational relationship between cognitive activity, anxiety and attributions [3] and also support the relationship between negatively toned cognitive activity during the day and distress in Harvey’s cognitive model [9]. However, as two of the attribution groupings were not fully mediated by sleep preoccupation, the relationship between anxiety, sleep preoccupation and attributions for insomnia is complex. Two possible routes could circumvent the mediational role of sleep preoccupation. The first, poor physical health and/or accompanying pain, could account for the partial mediation between anxiety and physical tension attributions. Although the present study excluded participants with uncontrolled chronic illnesses, participants with other chronic illnesses were included. It is likely that these participants see their insomnia as a by-product of their illness or the result of the medication they are taking and, thus, would be preoccupied with the illness rather than the lack of sleep. Therefore, a generalized measure of ‘health preoccupation’ may provide a useful insight into the relationship between anxiety and physical tension attributions. Against expectations, sleep preoccupation did not mediate the relationship between anxiety and cognitive arousal attributions. At best, this suggests that sleep preoccupation is secondary in the relationship between anxiety and cognitive arousal attributions. However, it would be logical to assume that under instances of extreme stress, individuals are more preoccupied with the stressor causing the insomnia than the resultant sleep loss.
An alternative explanation could be advanced by looking at the structure of the SDQ. Although previous research has conceptualized each dimension of the SDQ as a discrete causal attribution, there is the possibility that there are two main dimensions. This would fit with earlier hyperarousal models of insomnia that emphasized two discrete sleep-inhibitory factors: cognitive hyperarousal or somatic hyperarousal [20,21]. Cognitive hyperarousal would evolve from sleep effort to cognitive arousal attributions, and somatic arousal would be a continuum from sleep pattern problems to physical tension attributions. Several limitations must be acknowledged which affect the generalizability of the present findings. The sample is composed mainly of females and, although insomnia is more prevalent in women, the present distribution is greater still. Moreover, the self-selecting nature of the recruitment strategy clearly favors those with an interest in insomnia, which is confounded further by the low response rate. Future research would benefit from a larger, more representative sample of insomniacs. Similarly, the use of the SPS may be considered a disadvantage and, although valid and reliable in pilot work, further psychometric assessment is required. Finally, directionality between variables could not be confirmed. Where it would be logical to suggest that attributions would be an outcome of negatively toned activity and anxiety, the sequence between anxiety and cognitive activity is less clear. Indeed, Harvey’s model suggests a cumulative relationship which includes selective attention/monitoring and distorted perceptions, and the present study did not measure those specific constructs.
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J. Ellis et al. / Sleep Medicine 8 (2007) 277–280
Overall, addressing sleep preoccupation may go some way in preventing insomnia from becoming conditioned. On a broader level, a psycho-educational campaign targeted at older adults, which outlines normal age-related changes in sleep while also introducing a cognitive intervention, and which addresses the impact that preoccupation can have on sleep, could also be beneficial.
References [1] Vasey MW, Borkovec TD. Catastrophizing assessment of worrisome thoughts. Cogn Ther Res 1992;16:505–19. [2] Wicklow A, Espie CA. Intrusive thoughts and their relationship to actigraphic measurement of sleep: towards a cognitive model of insomnia. Behav Res Ther 2000;38:679–93. [3] Van Egeren L, Haynes SN, Franzen M, Hamilton J. Presleep cognitions and attributions in sleep-onset insomnia. J Behav Med 1983;6:217–32. [4] American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders (4th Edition) 1994. Washington DC: Author. [5] American Sleep Disorders Association. The International Classification of Sleep Disorders (2nd Edition) 2005. Rochester MN: Author. [6] Fichten CS, Creti L, Amsel R, Brender W, Weinstein N, Libman E. Poor sleepers who do not complain of insomnia: myths and realities about psychological and lifestyle characteristics of older good and poor sleepers. J Behav Med 1995;18(2):189–223. [7] Edinger JD, Fins AI, Glenn DM, Sullivan RJ, Bastian LA, Marsh GR, et al. Insomnia in the eye of the beholder. Are there clinical markers of objective sleep disturbances among adults with or without insomnia complaints. J Consult Clin Psychol 2000;64(4):586–93.
[8] Marchini EJ, Coates TJ, Magistad JG, Waldum SJ. What do insomniacs do, think, and feel during the day? A preliminary study. Sleep 1983;6:147–55. [9] Harvey AG. A cognitive model of insomnia. Behav. Res Ther 2002;40:869–93. [10] Ellis J, Hampson SE, Cropley M. Sleep hygiene or compensatory sleep practices: an examination of behaviours affecting sleep in older adults. Psychol Health Med 2002;7(2):157–62. [11] Morin CM, Espie CA. Insomnia: A clinical guide to assessment and treatment. New York: KluwerAcademic/Plenum Publishers; 2003. [12] Morin CM. Insomnia: Psychological assessment and management. New York: Guildford Press; 1993. [13] Crowley K, Colrain IM. Self-reported sleep patterns and daytime sleepiness in the neurologically healthy. J Sleep Res 2000;9:97–8. [14] Espie CA, Brooks DN, Lindsay WR. An evaluation of tailored psychological treatment of insomnia. J Behav Ther Exp Psychiatry 1989;20(2):143–53. [15] Espie CA, Inglis SJ, Harvey L, Tessier S. Insomniacs’ attributions: psychometric properties of the Dysfunctional Beliefs and Attitudes about Sleep Scale and the Sleep Disturbance Questionnaire. J Psychosom Res 2000;48:141–8. [16] Zigmund AS, Snaith RP. The Hospital Anxiety and Depression Scale. Acta Psychiatr Scand 1983;67:361–70. [17] Martin CR, Thompson DR. A psychometric evaluation of the Hospital Anxiety and Depression Scale in coronary care patients following acute myocardial infarction. Psychol Health Med 2000;5:193–201. [18] Ellis J, Fox P. Student mental health: Is there a role for sleep? J R Soc Promot Health 2004;124(3):129–33. [19] Ellis J, Cropley M, Hampson SE. The role of implicit and explicit processing in late-life insomnia. Sleep 2005;28(s):A115. [20] Lichstein KL, Rosenthal TL. Insomniacs’ perceptions of cognitive versus somatic determinants of sleep disturbance. J Abnorm Psychol 1980;89:105–7. [21] Nicassio PM, Mendlowitz DR, Fussell JJ, Petras L. The phenomenology of the pre-sleep state: the development of the pre-sleep arousal scale. Behav Res Ther 1985;23:263–71.
Brief Communication
The role of preoccupation in attributions for poor sleep Jason Ellis *, Sarah E. Hampson, Mark Cropley Department of Psychology, University of Surrey, Guildford, Surrey GU27XH, UK Received 18 November 2005; received in revised form 14 July 2006; accepted 14 August 2006 Available online 26 March 2007
Abstract Background and purpose: Studies examining the impact of daytime preoccupations with sleep are rare. The aim of the present study was to determine whether daytime preoccupations mediate the relationship between anxiety and attributions for poor sleep within older adults. Method: A cross-sectional study examined the mediational role of sleep preoccupations in the link between anxiety and attributions for poor sleep in a sample of late-life insomniacs (n = 92). Results: The findings show that a preoccupation with sleep during the day mediates the relationship between anxiety and both sleep effort and sleep pattern problem attributions but does not mediate cognitive arousal attributions for insomnia and only partially mediates the relationship between anxiety and physical tension attributions for insomnia. Conclusions: The results are discussed in terms of the existing models of insomnia and cognitive intervention strategies. Ó 2007 Published by Elsevier B.V. Keywords: Sleep preoccupation; Late-life insomnia; Attributions; Cognitive intrusion
1. Introduction A nighttime preoccupation with sleep has long been established as a key factor in preventing sleep-onset [1,2] and in attributions for sleep-onset insomnia [3]. However, there is little evidence on the effects of daytime preoccupations on attributions for poor sleep despite preoccupation and daytime distress being markers of insomnia under both the Diagnostic and Statistical Manual of Mental Disorders – 4th Edition (DSM-IV) [4] and International Classification of Sleep Disorders – 2nd Edition [5]. Interestingly, levels of daytime distress and, more specifically, levels of general anxiety discriminate insomniacs from non-complaining poor sleepers [6], and anxiety has been shown to be a better predictor of the presence of sleep complaints than total sleep time measured polysomnographically [7]. Moreover, the daytime thoughts of insomniacs are more focused on sleep than those of normal *
Corresponding author. Tel.: +44 1483686936; fax: +44 1483879553. E-mail address: [email protected] (J. Ellis).
1389-9457/$ - see front matter Ó 2007 Published by Elsevier B.V. doi:10.1016/j.sleep.2006.08.011
sleepers [8]. As such, the processes under which anxiety and daytime preoccupations interact, leading to attributions for insomnia, requires further attention. In terms of sleep-onset insomnia, one suggested pathway is sleep-related cognitions mediating the relationship between anxiety and attributions for sleep-onset insomnia [3]. Similarly, Harvey’s [9] cognitive model proposes an interaction between negatively toned daytime cognitive activity and distress. The aim of the present study was to determine whether daytime preoccupations mediate the relationship between anxiety and attributions for poor sleep within older adults. The University of Surrey Advisory Committee for Ethics approved the protocol for the study. 2. Method 2.1. Procedure Participants were recruited from an existing sample of late-life insomniacs (see [10] for details). They were
278
J. Ellis et al. / Sleep Medicine 8 (2007) 277–280
recruited through a magazine for older adults and were screened for insomnia using a 65-item structured sleep history assessment (see [11] for an example). Recruitment also incorporated the Insomnia Severity Index [12] and DSM-IV criteria for primary insomnia with one exception; certain chronic illnesses were included in the sample to retain ecological validity (e.g., HIV, controlled hypertension). However, those reporting uncontrolled illnesses that affect the central nervous system (e.g., uncontrolled Type 2 diabetes) were excluded because these illnesses directly affect sleep parameters [13]. Additionally, participants had previously been screened, and excluded, for neurological or psychiatric illnesses, other sleep disorders, or major depression (i.e., 611 on the Hospital Anxiety and Depression Scale (HADS)). Participants were contacted a year after the initial study and asked if they would like to take part in a study on daytime factors in insomnia (n = 246). They were sent a booklet containing the original screening/exclusion tools, the Sleep Disturbance Questionnaire (SDQ), HADS, and Sleep Preoccupation Scale (SPS). Of the 246 questionnaires sent, 128 (52.03%) were returned.
the SPS to have a high internal reliability in both student and older adult samples (a = .79 and .82, respectively) and to discriminate late-life insomniacs from normal sleepers [18,19]. In the present study, reliability was (a = .88). 2.4. Participants Of the 128 responses received, 26 participants were eliminated for having high levels of depression (P11 on the depression dimension of the HADS) and 10 participants were eliminated as they no longer met the criteria for insomnia. The final sample consisted of 92, 17 (18.5%) men and 75 (81.5%) women. The mean age of the sample was 70.90 (standard deviation (SD) 8.18) years, and the mean duration of insomnia was 13.20 years (SD 16.53). The mean score for anxiety was 8.85 (SD 2.98) and SPS was 36.55 (SD 11.75). Additionally, the mean SDQ score was 36.48 (SD 9.74) with the following for each dimension; physical tension (M 8.55, SD 2.88), cognitive arousal (M 10.70, SD 3.31), sleep pattern problems (M 9.43, SD 2.71), and sleep effort (M 7.79 SD 2.76). 2.5. Analytic strategy to examine mediation
2.2. Measures 2.2.1. Sleep Disturbance Questionnaire (SDQ) The SDQ [14] consists of 12 statements, scored on a five-point scale, relating to four dimensions: Physical Tension, Cognitive Arousal, Sleep Pattern Problems, and Sleep Effort. It measures causal attributions concerning the perceived source of sleep problems. The test demonstrates good reliability and internal reliabilities on the subscales range from a = 0.59–0.82 [15]. 2.3. Hospital Anxiety and Depression Scale (HADS) The HADS [16] examines depression and anxiety within non-psychiatric populations. It consists of 14 statements (7 relating to anxiety and 7 to depression) to which the respondent chooses one of four responses that best represents how they have felt over the past few weeks. The HADS has been used extensively on a wide variety of health issues, and both dimensions demonstrate a good internal reliability [17]. 2.3.1. Sleep Preoccupation Scale (SPS) The SPS assesses the frequency of sleep-related thoughts, feelings, or behaviors during the day. The SPS contains 20 statements, scored on a seven-point Likert-type scale: ‘1’ = Never to ‘7’ = Always. Scores range between 20 and 140, with higher scores indicating more sleep preoccupation. Items include ‘I cannot stop thinking about the sleep during the day’ and ‘I keep checking to see if I look tired’. Previous pilot-work has shown
To test mediation, three regression analyses were conducted on the total SDQ score and on each dimension. The first regression examined the relationship between predictor (i.e., anxiety) and mediator (i.e., SPS). The second examined the relationship between predictor and dependent variable (i.e., SDQ dimension score) and the final regression, both predictor and mediator on the dependent variable. If mediation exists, anxiety should be a significant predictor of both sleep preoccupation scores in the first regression and SDQ scores in the second regression but not a significant predictor (or significantly reduced, indicating partial mediation) of the SDQ score in the third regression, whereas SPS must be a significant predictor. 3. Results Results from the regression analyses showed that sleep preoccupation mediated the anxiety: the overall attribution relationship and, more specifically, the anxiety-sleep effort relationship and the anxiety-sleep pattern problem relationship. There was a partial mediational role of sleep preoccupation in the anxiety-physical tension relationship but no mediation between the anxiety-cognitive arousal relationship (Table 1). 4. Discussion Sleep preoccupation mediated overall attributions for poor sleep and, specifically, sleep effort and sleep pattern
J. Ellis et al. / Sleep Medicine 8 (2007) 277–280
279
Table 1 Regression analyses testing the mediational role of sleep preoccupation in attributions for late-life insomnia Predictor variable
Outcome variable
R2
R2 change
B
SEB
b
Anxiety
Sleep preoccupation
0.26
0.25
1.99
0.36
0.51***
Anxiety Anxiety + Sleep preoccupation
Total SDQ scores Total SDQ scores
0.20 0.22
0.19 0.21
1.46 0.02 0.11
0.31 0.10 0.03
0.45*** 0.02 0.46***
Anxiety Anxiety + Sleep preoccupation
Physical tension Physical tension
0.15 0.23
0.15 0.21
0.38 0.23 0.08
0.09 0.11 0.03
0.39*** 0.24* 0.31**
Anxiety Anxiety + Sleep preoccupation
Cognitive arousal Cognitive arousal
0.24 0.30
0.24 0.28
0.55 0.40 0.08
0.10 0.11 0.03
0.49*** 0.36*** 0.27*
Anxiety Anxiety + Sleep preoccupation
Sleep pattern problem Sleep pattern problem
0.10 0.19
0.09 0.17
0.29 0.13 0.08
0.09 0.10 0.03
0.32** 0.14 0.35**
Anxiety Anxiety + Sleep preoccupation
Sleep effort Sleep effort
0.07 0.22
0.06 0.21
0.24 0.02 0.11
0.09 0.10 0.03
0.26* 0.02 0.46***
* ** ***
= p < 0.05. = p < 0.005. = p < 0.001.
problem attributions. These findings are consistent with the hypothesized mediational relationship between cognitive activity, anxiety and attributions [3] and also support the relationship between negatively toned cognitive activity during the day and distress in Harvey’s cognitive model [9]. However, as two of the attribution groupings were not fully mediated by sleep preoccupation, the relationship between anxiety, sleep preoccupation and attributions for insomnia is complex. Two possible routes could circumvent the mediational role of sleep preoccupation. The first, poor physical health and/or accompanying pain, could account for the partial mediation between anxiety and physical tension attributions. Although the present study excluded participants with uncontrolled chronic illnesses, participants with other chronic illnesses were included. It is likely that these participants see their insomnia as a by-product of their illness or the result of the medication they are taking and, thus, would be preoccupied with the illness rather than the lack of sleep. Therefore, a generalized measure of ‘health preoccupation’ may provide a useful insight into the relationship between anxiety and physical tension attributions. Against expectations, sleep preoccupation did not mediate the relationship between anxiety and cognitive arousal attributions. At best, this suggests that sleep preoccupation is secondary in the relationship between anxiety and cognitive arousal attributions. However, it would be logical to assume that under instances of extreme stress, individuals are more preoccupied with the stressor causing the insomnia than the resultant sleep loss.
An alternative explanation could be advanced by looking at the structure of the SDQ. Although previous research has conceptualized each dimension of the SDQ as a discrete causal attribution, there is the possibility that there are two main dimensions. This would fit with earlier hyperarousal models of insomnia that emphasized two discrete sleep-inhibitory factors: cognitive hyperarousal or somatic hyperarousal [20,21]. Cognitive hyperarousal would evolve from sleep effort to cognitive arousal attributions, and somatic arousal would be a continuum from sleep pattern problems to physical tension attributions. Several limitations must be acknowledged which affect the generalizability of the present findings. The sample is composed mainly of females and, although insomnia is more prevalent in women, the present distribution is greater still. Moreover, the self-selecting nature of the recruitment strategy clearly favors those with an interest in insomnia, which is confounded further by the low response rate. Future research would benefit from a larger, more representative sample of insomniacs. Similarly, the use of the SPS may be considered a disadvantage and, although valid and reliable in pilot work, further psychometric assessment is required. Finally, directionality between variables could not be confirmed. Where it would be logical to suggest that attributions would be an outcome of negatively toned activity and anxiety, the sequence between anxiety and cognitive activity is less clear. Indeed, Harvey’s model suggests a cumulative relationship which includes selective attention/monitoring and distorted perceptions, and the present study did not measure those specific constructs.
280
J. Ellis et al. / Sleep Medicine 8 (2007) 277–280
Overall, addressing sleep preoccupation may go some way in preventing insomnia from becoming conditioned. On a broader level, a psycho-educational campaign targeted at older adults, which outlines normal age-related changes in sleep while also introducing a cognitive intervention, and which addresses the impact that preoccupation can have on sleep, could also be beneficial.
References [1] Vasey MW, Borkovec TD. Catastrophizing assessment of worrisome thoughts. Cogn Ther Res 1992;16:505–19. [2] Wicklow A, Espie CA. Intrusive thoughts and their relationship to actigraphic measurement of sleep: towards a cognitive model of insomnia. Behav Res Ther 2000;38:679–93. [3] Van Egeren L, Haynes SN, Franzen M, Hamilton J. Presleep cognitions and attributions in sleep-onset insomnia. J Behav Med 1983;6:217–32. [4] American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders (4th Edition) 1994. Washington DC: Author. [5] American Sleep Disorders Association. The International Classification of Sleep Disorders (2nd Edition) 2005. Rochester MN: Author. [6] Fichten CS, Creti L, Amsel R, Brender W, Weinstein N, Libman E. Poor sleepers who do not complain of insomnia: myths and realities about psychological and lifestyle characteristics of older good and poor sleepers. J Behav Med 1995;18(2):189–223. [7] Edinger JD, Fins AI, Glenn DM, Sullivan RJ, Bastian LA, Marsh GR, et al. Insomnia in the eye of the beholder. Are there clinical markers of objective sleep disturbances among adults with or without insomnia complaints. J Consult Clin Psychol 2000;64(4):586–93.
[8] Marchini EJ, Coates TJ, Magistad JG, Waldum SJ. What do insomniacs do, think, and feel during the day? A preliminary study. Sleep 1983;6:147–55. [9] Harvey AG. A cognitive model of insomnia. Behav. Res Ther 2002;40:869–93. [10] Ellis J, Hampson SE, Cropley M. Sleep hygiene or compensatory sleep practices: an examination of behaviours affecting sleep in older adults. Psychol Health Med 2002;7(2):157–62. [11] Morin CM, Espie CA. Insomnia: A clinical guide to assessment and treatment. New York: KluwerAcademic/Plenum Publishers; 2003. [12] Morin CM. Insomnia: Psychological assessment and management. New York: Guildford Press; 1993. [13] Crowley K, Colrain IM. Self-reported sleep patterns and daytime sleepiness in the neurologically healthy. J Sleep Res 2000;9:97–8. [14] Espie CA, Brooks DN, Lindsay WR. An evaluation of tailored psychological treatment of insomnia. J Behav Ther Exp Psychiatry 1989;20(2):143–53. [15] Espie CA, Inglis SJ, Harvey L, Tessier S. Insomniacs’ attributions: psychometric properties of the Dysfunctional Beliefs and Attitudes about Sleep Scale and the Sleep Disturbance Questionnaire. J Psychosom Res 2000;48:141–8. [16] Zigmund AS, Snaith RP. The Hospital Anxiety and Depression Scale. Acta Psychiatr Scand 1983;67:361–70. [17] Martin CR, Thompson DR. A psychometric evaluation of the Hospital Anxiety and Depression Scale in coronary care patients following acute myocardial infarction. Psychol Health Med 2000;5:193–201. [18] Ellis J, Fox P. Student mental health: Is there a role for sleep? J R Soc Promot Health 2004;124(3):129–33. [19] Ellis J, Cropley M, Hampson SE. The role of implicit and explicit processing in late-life insomnia. Sleep 2005;28(s):A115. [20] Lichstein KL, Rosenthal TL. Insomniacs’ perceptions of cognitive versus somatic determinants of sleep disturbance. J Abnorm Psychol 1980;89:105–7. [21] Nicassio PM, Mendlowitz DR, Fussell JJ, Petras L. The phenomenology of the pre-sleep state: the development of the pre-sleep arousal scale. Behav Res Ther 1985;23:263–71.