Insomnia and paranoia.pdf

Insomnia and paranoia

Daniel Freeman, Katherine Pugh, Natasha Vorontsova, and Laura SouthgateDepartment of Psychology, Institute of Psychiatry, King's College London, United Kingdom.

AbstractInsomnia is a potential cause of anxiety, depression, and anomalies of experience; separate researchhas shown that anxiety, depression and anomalies of experience are predictors of paranoia. Thusinsomnia may contribute to the formation and maintenance of persecutory ideation. The aim was toexamine for the first time the association of insomnia symptoms and paranoia in the generalpopulation and the extent of insomnia in individuals with persecutory delusions attending psychiatricservices. Assessments of insomnia, persecutory ideation, anxiety, and depression were completedby 300 individuals from the general population and 30 individuals with persecutory delusions and adiagnosis of non-affective psychosis. Insomnia symptoms were clearly associated with higher levelsof persecutory ideation. Consistent with the theoretical understanding of paranoia, the associationwas partly explained by the presence of anxiety and depression. Moderate or severe insomnia waspresent in more than 50% of the delusions group. The study provides the first direct evidence thatinsomnia is common in individuals with high levels of paranoia. It is plausible that sleep difficultiescontribute to the development of persecutory ideation. The intriguing implication is that insomniainterventions for this group could have the added benefit of lessening paranoia.

KeywordsDelusions; Persecutory; Paranoia; Insomnia; Psychosis

1IntroductionClinical experience indicates that many individuals with persecutory delusions have difficultiesinitiating and maintaining sleep. The extent of the problem has never been reported. Often theinsomnia is simply a result of insufficient activity during the day and early retirement to bed.However the relationship between insomnia and paranoia may hold greater clinical andtheoretical interest. The stressful experience of insomnia may lead to the lowering of moodand anomalies of experience that drive persecutory ideation. The intriguing clinical implicationis that simple well-established interventions for sleep difficulties could lessen paranoidexperience.

There is evidence consistent with the idea that sleep disturbance has a role in the developmentof paranoia. Insomnia is a risk factor for the development of emotional disorder (Ford and

2009 Elsevier B.V.This document may be redistributed and reused, subject to certain conditions.

Corresponding author. Psychology Department, PO Box 077, Institute of Psychiatry, King's College London, Denmark Hill, LondonSE5 8AF, United Kingdom. E-mail: [email protected] document was posted here by permission of the publisher. At the time of deposit, it included all changes made during peer review,copyediting, and publishing. The U.S. National Library of Medicine is responsible for all links within the document and for incorporatingany publisher-supplied amendments or retractions issued subsequently. The published journal article, guaranteed to be such by Elsevier,is available for free, on ScienceDirect.

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Kamerow, 1989; Breslau et al., 1996; Morphy et al., 2007) and an association with daytimemood disturbance has been repeatedly demonstrated (Riedel and Lichstein, 2000; Buysse etal., 2007). In separate research, paranoia has been strongly linked with negative affect (Freemanet al., 2008b; Bentall et al., in press), even being considered a type of anxious fear (Freemanand Freeman, 2008). Therefore insomnia may be one cause of the negative mood that leads toparanoia. Anomalies of experience such as perceptual distortions and hallucinations are alsoconsidered a key cause of paranoia (Maher, 1988; Freeman et al., 2008a); therefore it isgermane that sleep deprivation has long been noted to produce temporary psychotic-likeexperiences (Luby et al., 1960; West et al., 1962). Sleep difficulties are a common prodromalfeature of schizophrenia (Birchwood et al., 1989; Yung and McGorry, 1996) and even inunmedicated patients with schizophrenia there is evidence of increased sleep latency anddecreased total sleep time (Chouinard et al., 2004). At a neurobiological level it has beensuggested that the overactivity of dopamine D2 receptors in the striatum thought to underliethe positive symptoms of schizophrenia also enhances wakefulness (Monti and Monti, 2005).

Recent research demonstrates that paranoid thinking is much more common in the generalpopulation than previously thought (Freeman et al., 2008b). A high prevalence of insomniahas been recognised for longer. Approximately 30% of the general population experiencesymptoms of insomnia, with a third of this group having chronic insomnia (Ohayon, 2002;Walsh, 2004; Morin et al., 2006). This sleep disturbance is associated with anxiety anddepression (Taylor et al., 2005; Breslau et al., 1996; Buckner et al., 2008); indeed, difficultiesfalling or staying asleep are a symptom of the diagnoses of depression, generalised anxietydisorder, and post-traumatic stress disorder (APA, 2000). In the current study the aim was todetermine whether persecutory ideation and insomnia are associated. A community samplewas used to obtain a range in paranoia severity and avoid the complicating issues of neurolepticmedication and high levels of inactivity. At the same time the occurrence of insomnia in agroup of patients with persecutory delusions attending psychiatric services for psychosis wasalso examined.

2Method2.1Participants

The community sample comprised 300 individuals. There were three entry criteria: aged 18 orabove; able to read and write in English; and no history of treatment for severe mental illness(e.g. schizophrenia, bipolar disorder). The sample was recruited via the distribution to localpostcodes of leaflets advertising research studies at King's College London. Those whoresponded to the leaflet were screened for the entry criteria over the telephone. Questionnaireswere then completed at King's College London, by postal return or an Internet website (onlyavailable to screened individuals). The clinical group was recruited from adult services in theSouth London and Maudsley NHS Foundation Trust. The entry criteria were the presence ofa current persecutory delusion, which met the criteria of Freeman and Garety (2000), and aclinical diagnosis of schizophrenia, schizo-affective disorder, or delusional disorder (i.e.nonaffective psychosis).

2.2Measures2.2.1Insomnia Severity Index (ISI) (Bastien et al., 2001)The ISI is a seven-itemself-report questionnaire based upon the insomnia criteria of the Diagnostic and StatisticalManual of Mental Disorders (APA, 1994). The scale assesses sleep-onset and sleepmaintenance difficulties, associated distress, and interference with daily functioning. Each itemis rated on a 04 scale. The time period is the past fortnight. Higher scores indicate the presenceof symptoms of insomnia. The scale was evaluated in a sample of over two hundred individualsattending a sleep disorders clinic, and has been repeatedly used in insomnia studies (Buckner

Freeman et al. Page 2


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et al., 2008; Savard et al., 2005; Bernert et al., 2007). The questionnaire shows convergentvalidity with daily sleep diaries, significant other reports and clinician ratings. In the currentstudy the scale showed high internal reliability (Cronbach's Alpha = .89). The guidelines forthe interpretation of scores are: no clinically significant insomnia (07), subthreshold insomnia(814), clinical insomnia of moderate severity (1521) and severe clinical insomnia (2228).

2.2.2Sleep-50 Questionnaire (Spoormaker et al., 2005)The nine-item insomniasubscale of the Sleep-50 Questionnaire assesses difficulties falling and staying asleep over thepast month, but not interference with daily functioning. Each item is rated on a scale of 1 to 4.Higher scores indicate the presence of symptoms of insomnia. The scale was psychometricallyevaluated in a sample of 400 students and 250 sleep clinic patients. In the current study theinternal reliability of the scale was high (Cronbach's Alpha = .88). Clinical insomnia isindicated by a score of 19 or above.

2.2.3Green et al. Paranoid Thoughts Scale Part B (Green et al., 2008)TheG-PTS Part B is a self-report measure of the occurrence of persecutory ideation in the pastmonth. Each of the sixteen items (e.g. I was convinced there was a conspiracy against me,Certain individuals have had it in for me, I have definitely been persecuted) is rated on ascale from 1 to 5, and conforms to a clear definition of persecutory ideation (Freeman andGarety, 2000). The total score can range from 16 to 80. Higher scores indicate greater levelsof persecutory thinking. The questionnaire has been psychometrically evaluated for use in bothclinical and non-clinical populations. The internal consistency of the scale and testretestreliability are good. Convergent validity with the Paranoia Scale (Fenigstein and Vanable,1992) has been shown. In the current study the scale had very high internal reliability(Cronbach's Alpha = .94).

2.2.4Depression Anxiety Stress Scales (Lovibond and Lovibond, 1995)TheDASS is a 42-item instrument with three subscales measuring symptoms of depression,anxiety, and stress over the past week. Each of the subscales consists of 14 items with a 03scale (0 = did not apply to me at all, 3 = applied to me very much). Higher scores indicatehigher levels of emotional distress. The scale has been shown to be reliable and valid in largeclinical and non-clinical populations (Brown et al., 1997; Crawford and Henry, 2003; Page etal., 2007). The anxiety and depression sub-scales were used; each showed very high internalreliability in the current study (Anxiety Cronbach's Alpha = .91, Depression Cronbach'sAlpha = .96). There are no items on the scales that assess sleep difficulties.

2.3AnalysisAnalyses were carried out using Stata Version 10.0 (StataCorp, 2008). Visual inspectionshowed that the measures of persecutory ideation, anxiety and depression in the communitysample all showed considerable positive skew; 46.7%, 34.3% and 31.0% had the minimumscores on the measures of paranoia, depression and anxiety respectively. These variables weretherefore recoded into ordinal categories: Paranoia (16, 1720, 2124, 2528, 29+), Depression(0, 13, 46, 79, 1012, 13+), Anxiety (0, 13, 46, 79, 10+). The main analyses were ordinallogistic regressions (using the Stata ologit command) with paranoia as the dependent variable.In the first stage insomnia was the independent variable (controlling for age, sex, and workingstatus). In the second stage depression was added as an additional independent variable. In thefinal stage anxiety was added to the model. This procedure was carried out separately for eachof the insomnia scales. There were no missing data. The models were repeated adding the datafor ethnicity and education level, which had missing data for three cases, but the results wereunaltered. 95% Confidence Intervals (CI) are reported.



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3Results3.1Community group

The community group comprised 140 men and 160 women. The mean age was 37.7(SD = 12.5). The reported ethnicities were: White (n = 216), Black-Caribbean (n = 16), BlackAfrican (n = 18), Black-Other (n = 6), Indian (n = 6), Pakistani (n = 1), and other (n = 35). Onehundred and six participants were working full-time, seventy were working part-time, thirteenwere retired, sixty-four were unemployed and forty-seven were students. The educationalqualifications were: none (n = 19), GCSE (n = 57), AS/A-level (n = 41), diploma (n = 32),degree (n = 97), postgraduate degree (n = 53).

Scores on the measures are shown in Table 1. Based on the Insomnia Severity Index, 216 (72%)participants had no clinically significant insomnia, 62 (20.7%) participants had sub-thresholdinsomnia, 17 (5.7%) participants had clinical insomnia of moderate severity and 5 (1.7%)participants had severe clinical insomnia. Therefore 28% of the community sample had somedegree of sleep difficulty. There was a high correlation between ISI and Sleep-50 Insomniascores, r = .83, p < .001. Forty-six individuals (15.3%) scored above the cut-off on the Sleep-50,indicating potential clinical insomnia.

Ordinal logistic regressions examining the association of paranoia and insomnia are reportedin Table 2. There is a strong association of the insomnia scales with paranoia. For theinterpretation of the results it should be remembered that the odds ratios for the insomnia scalesrefer to one-point changes. A ten-point increase in the Insomnia Severity Index is associatedwith an odds ratio of 4.4 for an increase in paranoia category (1.16 raised to the power of 10).A ten-point increase on the Sleep-50 scale is associated with an odds ratio of 6.2 for an increasealong the paranoia ordinal scale. 70% of those in the highest category of paranoia scores hadat least sub-threshold insomnia difficulties as assessed by the ISI, whereas this was the casefor only 17% of the participants without any paranoid ideation. On the Sleep-50 questionnaire,59% in the highest paranoia category scored above the cut-off for insomnia, whereas only 8%in the lowest paranoia category scored similarly. It can be seen that when depression is addedto the regression models that the relationship of insomnia to paranoia is lessened but that thereis a unique contribution of each variable to predicting paranoia scores. When anxiety is addedthen the relationship of insomnia to paranoia is lessened substantially further, becomingstatistically non-significant for the ISI.

3.2Clinical groupThe persecutory delusions group comprised 18 men and 12 women. The mean age was 44.2(SD = 11.7). The reported ethnicities were: White (n = 16), Black-Caribbean (n = 3), BlackAfrican (n = 5), Black-Other (n = 3), Indian (n = 1), and other (n = 2). Twenty-two patientswere unemployed, three were working part-time, three were retired, and one was a student.The educational qualifications were: none (n = 6), GCSE (n = 10), AS/A-level (n = 5), diploma(n = 6), degree (n = 1), postgraduate degree (n = 2). The diagnoses were: schizophrenia(n = 24), schizo-affective disorder (n = 4) and delusional disorder (n = 2). Antipsychoticmedication data were converted into chlorpromazine equivalents grouped into low (0200 mg),medium (200400 mg) and high ( 400 mg); one person was not taking any medication, elevenwere on a low dose, fourteen were on a medium dose and four were on a high dose. Sevenpatients were taking clozapine, seventeen patients were taking other atypical antipsychotics,and five people were on typical antipsychotic medication. Five patients were being prescribedtwo different antipsychotic drugs.

The prevalence of insomnia in the persecutory delusions group as assessed by the ISI was: 27%(n = 8) severe clinical insomnia, 27% (n = 8) clinical insomnia of moderate severity, and 30%



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(n = 9) subthreshold insomnia. Only 17% (n = 5) had no clinically significant insomnia. Therewas a high correlation between ISI and Sleep-50 scores, r = .78, p < .001. Sixty percent(n = 18) of the persecutory delusions group scored above the Sleep-50 insomnia cut-off. Scoresdid not differ by medication level on the ISI, F(2, 26) = .137, p =.872, or the Sleep-50, F(2,26) = .350, p = .708.

4DiscussionThe rates of sleep difficulties in the community sample were consistent with theepidemiological literature; almost 30% had symptoms of insomnia and approximately 10%were in the clinical range. But the unique focus of the study was on a potential associationbetween sleep difficulties and paranoid thinking. The results were clear: higher levels ofinsomnia were associated with higher levels of persecutory thinking. Confirmation wasprovided by the high prevalence of insomnia in the individuals with clinical paranoia. Insomniais most likely an overlooked problem in psychiatric services for individuals with persecutorydelusions.

Sleep disturbance is already incorporated into a theoretical account of persecutory delusions(Freeman et al., 2006), but its role had not been directly tested. In this study the relationshipbetween sleep and paranoia was largely accounted for by levels of anxiety and depression. Thisis unsurprising; both paranoia and sleep difficulties are closely linked with negative affect.Nevertheless the mediating routes between insomnia and paranoia require closer (and morerigorous) examination. A second plausible route is via the occurrence of perceptual anomalies.A lack of sleep may cause a puzzling internal state for the individual that, in the context ofanxiety, is incorrectly attributed to external threat. Study of the mechanisms underlyinginsomnia in patients with persecutory delusions is also needed; sleep disturbance may be partlymaintained by established insomnia-related processes such as rumination, attention to sleep-related threat, and dysfunctional beliefs about sleep (Harvey et al., 2005).

The representativeness of the samples in the current study is questionable; the communitygroup was only a minority of the many people leafleted in the local postcodes, while the clinicalgroup was of a small size. There was also a reliance on self-report assessments. The studyfocussed on a specific experience (paranoid ideation), but it could be argued that completionof a full diagnostic screening interview by the non-clinical population would have providedinformation of interest. However the key limitation of the study is the cross-sectional design.The causal direction of the relationship between insomnia and paranoia is unknown. It isplausible that the insomnia assessed is simply a consequence of living with paranoid fears,although a circular relationship between insomnia, anxiety and paranoia is more probable.Longitudinal studies of the relationships are clearly warranted. A priority is the evaluation ofwell-established insomnia interventions (e.g. Espie, 2006; Harvey et al., 2007) for individualswith delusions. These interventions will provide a stronger test of the causal relationshipbetween insomnia and paranoia and hold the promise of enhancing the efficacy of treatmentsfor delusional beliefs.

Role of funding sourceFunding for this study was provided by a Fellowship awarded by the Wellcome Trust to Dr.Daniel Freeman. The Wellcome Trust had no further role in study design; in the collection,analysis and interpretation of data; in the writing of the report; and in the decision to submitthe paper for publication.



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ContributorsDaniel Freeman designed the study, analysed the data and wrote the paper. Katherine Pugh,Natasha Vorontsova, and Laura Southgate collected the data and commented upon themanuscript.

Conflict of interestThere were no conflicts of interest.

AcknowledgementThe research was funded by a Wellcome Trust Fellowship awarded to Dr. Daniel Freeman.

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Table 1Questionnaire scores

Community group (N = 300) Persecutory delusions group (N = 30)

Mean SD Min.Max. Mean SD Min.Max.

Insomnia Severity Index 5.90 5.17 028 15.07 7.34 027

Sleep-50 Insomnia 13.89 4.95 935 23.07 8.44 1136

GPTS-Part B (persecutoryideation)

19.94 7.85 1673 65.27 13.49 3980

DASS Depression 4.42 6.99 042 26.63 11.17 241

DASS Anxiety 3.32 5.56 038 21.93 10.90 441


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Table 2Ordinal logistic regressions for the community sample (N = 300) with paranoia as the dependent variable and controllingfor age, sex and work status

Odds ratio p-value 95% CI

1. Insomnia Severity Index 1.16 < .001 1.11, 1.22

2. Insomnia Severity Index 1.09 < .001 1.04, 1.15

Depression 1.73 < .001 1.46, 2.03

3. Insomnia Severity Index 1.04 .180 .98, 1.09

Depression 1.33 .002 1.11, 1.60

Anxiety 2.22 < .001 1.67, 2.96

1. Sleep-50 Insomnia 1.20 < .001 1.14, 1.26

2. Sleep-50 Insomnia 1.13 < .001 1.07, 1.19

Depression 1.67 < .001 1.41, 1.97

3. Sleep-50 Insomnia 1.07 .024 1.01, 1.13

Depression 1.31 .004 1.09, 1.58

Anxiety 2.12 < .001 1.59, 2.82


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Insomnia and paranoia.pdf