Nocturnal and daytime panic attacks--comparison of sleep architecture, heart rate variability, and response to sodium lactate challenge

Comparison of Sodium Lactate Infusion and Carbon Dioxide Inhalation Panic Provocation Tests: A Meta-analysis

BACKGROUND

Sodium lactate (NaL) infusion and carbon dioxide (CO₂) inhalation are proven to provoke acute panic attacks (PAs) in patients with panic disorder (PD). A systematic literature search and meta-analysis were performed to compare the effect sizes of these methods.

METHODS

Odds ratios were calculated for each of the original studies and were pooled using the random-effects model.

RESULTS

Either NaL or CO₂ provocations significantly increased the rates of PAs in individuals with PD compared to those in healthy controls. However, the effect size of NaL infusion (OR=25.13, 95% CI=15.48-40.80) was significantly greater than that of CO₂ inhalation (OR=10.58, 95%CI=7.88-14.21).

CONCLUSION

The evidence for the efficacy of the two panic provocation tests is very strong. Yet, the results support the superiority of NaL infusion over CO₂ inhalation challenge as a panic provocation test. Thus, lactate seems a much stronger stimulus than CO₂ for the brain suffocation detector.

The Association between Insomnia and Anxiety Symptoms in a Naturalistic Anxiety Treatment Setting

Objective/Background: Few studies have examined the relationship between insomnia and anxiety treatment outcomes in naturalistic settings. Furthermore, prior studies typically examine insomnia within a single anxiety diagnosis without accounting for the high overlap between disorders. Here we investigate the association between insomnia and multiple anxiety disorders over a course of cognitive behavioral treatment (CBT) in a naturalistic treatment setting. Participants: Insomnia was assessed in 326 patients seeking treatment at a clinic specializing in CBT for anxiety. Methods: Multilevel modeling was used to investigate whether insomnia moderated reductions in anxiety symptoms. A cross-lagged analysis tested for bidirectional effects between insomnia and anxiety. Multiple regression was used to investigate the relationship between insomnia and anxiety while controlling for the other anxiety disorders and depression. Results: While there was a significant reduction in insomnia during treatment in all anxiety disorders, the majority of the most severe patients remained in the clinical range at post-treatment. Baseline insomnia did not significantly moderate anxiety outcomes, suggesting that patients with high or low levels of insomnia will do equally well in CBT for anxiety. The bidirectional effect between insomnia and anxiety did not reach significance. Additionally, posttraumatic stress disorder, generalized anxiety disorder, and panic disorder were associated with the greatest endorsement of insomnia, after controlling for the overlap between disorders. Conclusions: Sleep problems may persist after anxiety treatment, suggesting that CBT for insomnia may be warranted during or after a course of CBT for anxiety. Importantly, baseline insomnia does not impede anxiety reduction during CBT.

Sleep disturbance in PTSD and other anxiety-related disorders: an updated review of clinical features, physiological characteristics, and psychological and neurobiological mechanisms

The current report provides an updated review of sleep disturbance in posttraumatic stress disorder and anxiety-related disorders. First, this review provides a summary description of the unique and overlapping clinical characteristics and physiological features of sleep disturbance in specific DSM anxiety-related disorders. Second, this review presents evidence of a bidirectional relationship between sleep disturbance and anxiety-related disorders, and provides a model to explain this relationship by integrating research on psychological and neurocognitive processes with a current understanding of neurobiological pathways. A heuristic neurobiological framework for understanding the bidirectional relationship between abnormalities in sleep and anxiety-related brain pathways is presented. Directions for future research are suggested.

Sleep and mental disorders: A meta-analysis of polysomnographic research

Investigating sleep in mental disorders has the potential to reveal both disorder-specific and transdiagnostic psychophysiological mechanisms. This meta-analysis aimed at determining the polysomnographic (PSG) characteristics of several mental disorders. Relevant studies were searched through standard strategies. Controlled PSG studies evaluating sleep in affective, anxiety, eating, pervasive developmental, borderline and antisocial personality disorders, attention-deficit-hyperactivity disorder (ADHD), and schizophrenia were included. PSG variables of sleep continuity, depth, and architecture, as well as rapid-eye movement (REM) sleep were considered. Calculations were performed with the "Comprehensive Meta-Analysis" and "R" software. Using random effects modeling, for each disorder and each variable, a separate meta-analysis was conducted if at least 3 studies were available for calculation of effect sizes as standardized means (Hedges' g). Sources of variability, that is, sex, age, and mental disorders comorbidity, were evaluated in subgroup analyses. Sleep alterations were evidenced in all disorders, with the exception of ADHD and seasonal affective disorders. Sleep continuity problems were observed in most mental disorders. Sleep depth and REM pressure alterations were associated with affective, anxiety, autism and schizophrenia disorders. Comorbidity was associated with enhanced REM sleep pressure and more inhibition of sleep depth. No sleep parameter was exclusively altered in 1 condition; however, no 2 conditions shared the same PSG profile. Sleep continuity disturbances imply a transdiagnostic imbalance in the arousal system likely representing a basic dimension of mental health. Sleep depth and REM variables might play a key role in psychiatric comorbidity processes. Constellations of sleep alterations may define distinct disorders better than alterations in 1 single variable. (PsycINFO Database Record

A systematic review of sleep disturbance in anxiety and related disorders

Recent research suggests that sleep disturbance may be a transdiagnostic process, and there is increasing interest in examining how sleep disturbance may contribute to anxiety and related disorders. The current review summarizes and synthesizes the extant research assessing sleep in anxiety and related disorders. The findings suggest that sleep disturbance exacerbates symptom severity in the majority of anxiety and related disorders. However, the nature of sleep disturbance often varies as a function of objective versus subjective assessment. Although sleep disturbance is a correlate of most anxiety and related disorders, a causal role for sleep disturbance is less clear. A model of potential mechanisms by which sleep disturbance may confer risk for the development of anxiety and related disorders is discussed. Future research integrating findings from basic sleep research with current knowledge of anxiety and related disorders may facilitate the development of novel treatments for comorbid sleep disturbance and clinical anxiety.

Heart rate and respiratory response to doxapram in patients with panic disorder

Panic disorder (PD) is characterized by anticipatory anxiety and panic, both causing physiological arousal. We investigated the differential responses between anticipatory anxiety and panic in PD and healthy controls (HC). Subjects (15 PD and 30 HC) received an injection of a respiratory stimulant, doxapram, with a high rate of producing panic attacks in PD patients, or an injection of saline. PD subjects had significantly higher scores in anxiety and panic symptoms during both conditions. Analysis of heart rate variability (HRV) indices showed higher sympathetic activity (LF) during anticipatory anxiety and panic states, an increase in the ratio of LF/HF during the anticipatory and panic states and a decrease in parasympathetic (HF) component in PD patients. During doxapram PD subjects increased their LF/HF ratio while HC had a reduction in LF/HF. Parasympathetic component of HRV was lower during anticipatory anxiety in PD. In general, PD showed greater sympathetic and psychological responses related to anxiety and sensations of dyspnea, reduced parasympathetic responses during anticipatory and panic states, but no differences in respiratory response. This confirms previous studies showing that PD patients do not have an intrinsic respiratory abnormality (either heightened or dysregulated) at the level of the brain stem but rather an exaggerated fear response.

Subjective sleep quality in relation to inhibition and heart rate variability in patients with panic disorder

BACKGROUND

Patients with panic disorder (PD) are known to report impaired sleep quality and symptoms of insomnia. PD is an anxiety disorder characterised by deficient physiological regulation as measured by heart rate variability (HRV), and reduced HRV, PD and insomnia have all been related to impaired inhibitory ability. The present study aimed to investigate the interrelationships between subjectively reported sleep impairment, cognitive inhibition and vagally mediated HRV in a sample characterised by variability on measures of all these constructs.

METHODS

Thirty-six patients with PD with or without agoraphobia were included. Cognitive inhibition was assessed with the Color-Word Interference Test from the Delis-Kaplan Executive Function System (D-KEFS), HRV was measured using high frequency (HF) power (ms(2)), and subjectively reported sleep quality was measured with the Pittsburgh Sleep Quality Index (PSQI).

RESULTS

Cognitive inhibition was related to both Sleep latency and Sleep disturbances, whereas HRV was only related to Sleep disturbances. These relationships were significant also after controlling for depression.

LIMITATIONS

Correlational design.

CONCLUSION

Cognitive inhibition is related to key insomnia symptoms: sleep initiation and sleep maintenance. The data supports the psychobiological inhibition model of insomnia, and extends previous findings. Possible clinical implications of these findings are discussed.

Efficacy of Two Cognitive-Behavioral Treatment Modalities for Panic Disorder With Nocturnal Panic Attacks

The aim of this research was to examine the efficacy of two cognitive-behavioral treatment modalities for panic disorder (PD) with nocturnal panic (NP). The first study was conducted to determine whether conventional CBT for PD was effective for PD with NP in three participants. A second study sought to explore whether a CBT adapted to NP would lead to different clinical outcomes in three other participants. A multiple-baseline single-case design across individuals was used in both studies. Treatment outcome was assessed with standardized clinician ratings, self-report questionnaires, and daily self-monitoring. Results revealed that both the conventional and the adapted treatments showed a faster decrease in NPs versus daytime panics and significant clinical changes in all measures for up to a year after therapy. Hence, the changes brought about by the adapted treatment seemed to be similar to those obtained using conventional treatment. In light of these results, it can be presumed that conventional strategies may be sufficient for the treatment of NP. These observations raise questions regarding the real need to adapt treatments specifically to NP.

Is nocturnal panic a distinct disease category? Comparison of clinical characteristics among patients with primary nocturnal panic, daytime panic, and coexistence of nocturnal and daytime panic

OBJECTIVE

Many patients with panic disorder (PD) experience nocturnal panic attacks. We investigated the differences in demographic variables and symptom characteristics as well as response to treatment among patients with primary day panic (DP), primary nocturnal panic (NP), and the coexistence of DP and NP (DP/NP), and discuss whether NP is a distinct disease category.

METHOD

One hundred one consecutive untreated patients with PD were enrolled and subsequently divided into the NP, DP, and DP/NP groups. The presence of 13 panic attack symptom items as well as scores on the Panic Disorder Severity Scale (PDSS) and the Pittsburgh Sleep Quality Index (PSQI) were compared among the groups. After 3 months of regular treatment, PDSS scores were assessed again to evaluate treatment response.

RESULTS

Nocturnal panic attacks of the participants were mostly reported to occur in the first tertile of nocturnal sleep. The number of males, onset age, and presence of choking sensation were significantly higher, and the PDSS score was significantly lower in the NP group compared with the other groups. The DP/NP group showed the highest PDSS score, and participants in this group were prescribed the highest doses of medication among all groups. Only diagnostic sub-category was significantly associated with treatment response. The total score for PDSS and PSQI correlated significantly only in the NP group.

CONCLUSIONS

DP/NP could be a severe form of PD, while primary NP could be a relatively mild subcategory that may partially share common pathophysiology with adult type night terror.

Sleep and anxiety disorders

Sleep disturbances-particularly insomnia - are highly prevalent in anxiety disorders and complaints such as insomnia or nightmares have even been incorporated in some anxiety disorder definitions, such as generalized anxiety disorder and posttraumatic stress disorder. In the first part of this review, the relationship between sleep and anxiety is discussed in terms of adaptive response to stress. Recent studies suggested that the corticotropin-releasing hormone system and the locus ceruleus-autonomic nervous system may play major roles in the arousal response to stress. It has been suggested that these systems may be particularly vulnerable to prolonged or repeated stress, further leading to a dysfunctional arousal state and pathological anxiety states, Polysomnographic studies documented limited alteration of sleep in anxiety disorders. There is some indication for alteration in sleep maintenance in generalized anxiety disorder and for both sleep initiation and maintenance in panic disorder; no clear picture emerges for obsessive-compulsive disorder or posttraumatic stress disorder. Finally, an unequivocal sleep architecture profile that could specifically relate to a particular anxiety disorder could not be evidenced; in contrast, conflicting results are often found for the same disorder. Discrepancies between studies could have been related to illness severity, diagnostic comorbidity, and duration of illness. A brief treatment approach for each anxiety disorder is also suggested with a special focus on sleep.

Quality of sleep in escitalopram-treated female patients with panic disorder

OBJECTIVE

The purpose of this study was to assess the development of the night-activity rhythm and quality of sleep during escitalopram treatment of patients suffering from panic disorder.

METHODS

Fifteen women with panic disorder were included and followed-up over a 5-week study period during treatment with escitalopram. An age-matched control group of 15 women were also assessed for 1 week. Motor activity was continuously measured with an electronic wrist device (Actiwatch), sleep was assessed with the Pittsburgh sleep quality index (PSQI) and patients were clinically assessed with the panic and agoraphobic scale (P&A), the global assessment of functioning (GAF) score, the Hamilton depression and anxiety scales (HAM-D, HAM-A) and the clinical global impression (CGI) score.

RESULTS

There was a statistically significant difference on the self-rated PSQI between the panic disorder patients and the control group. This difference disappeared after 4 weeks of treatment with escitalopram. There was no statistically significant difference of the objective measurements of the Actiwatch between the patients and the control group. In addition, no statistically significant changes were found in the actigraphy measurements at the beginning and the end of the treatment period for patients with panic disorder.

CONCLUSIONS

Patients with panic disorder rate their sleep worse than healthy controls. Treatment with escitalopram improved the subjective quality of sleep, whereas objective measures remained unchanged during treatment.

Subtypes of panic attacks: a critical review of the empirical literature

BACKGROUND

Panic disorder is a heterogeneous disorder, comprising a variety of somatic, physiological, and cognitive symptoms during repeated panic attacks. As a result, considerable data have examined whether panic attacks may be classified into distinct diagnostic or functional subtypes. The aim of this study is to evaluate the existing literature regarding the validity of panic attack subtypes.

METHODS

This review focuses on data published since 2000, with the publication of DSM-IV-TR, augmented by replicated data published since 1980, with the publication of DSM-III and subsequently DSM-IV. Published reports evaluating empirical evidence for the validity of panic attack subtypes are reviewed.

RESULTS

Five sets of panic symptoms (respiratory, nocturnal, nonfearful, cognitive, and vestibular) have been shown to cluster together at varying degrees of consistency. However, none of these potential subtypes have been associated with sufficient and reliable external validation criteria indicative of functional differences. This apparent lack of findings may be related to methodological inconsistencies or limitations across the reviewed studies.

CONCLUSIONS

Although at present the data do not warrant the utility of subtyping, further research aimed at patent gaps in the literature, including clearer operationalization of symptom subtypes, greater use of biological challenge paradigms and physiological and other more objective measures of fear and anxiety, and exploration of subtyping based on biological factors such as genetics, may support the future designation of panic attack subtypes and their ultimate clinical utility.

Anxiety and sleep problems: emerging concepts and theoretical treatment implications

The high prevalence and comorbidity of anxiety and sleep problems, especially insomnia, suggest an important underlying relationship between these disorders. In this article, we highlight two theoretical models explaining this co-occurrence, provide a brief update on the association between anxiety-insomnia and anxiety-cataplexy in general, and review more specifically sleep problems in generalized anxiety, post-traumatic stress disorder, and panic disorder. We also explore sleep paralysis as an anxiety-sleep event. Our goal with this examination of selective anxiety-sleep problems is to provide clues about diagnostic and treatment approaches and frame strategies for future research.

Effect of medication and psychotherapy on heart rate variability in panic disorder

BACKGROUND

Panic disorder (PD) patients have been shown to have reduced heart rate variability (HRV). Low HRV has been associated with elevated risk for cardiovascular disease. Our aim was to investigate the effects of treatment on heart rate (HR) in patients with PD through a hyperventilation challenge.

METHODS

We studied 54 participants, 43 with Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) PD and 11 controls. Subjects lay supine with their heads in a plastic canopy chamber, resting for 15 min and then breathing at a rate of 30 breaths per minute for 10 min. HRV was sampled for spectral analysis. Clinical and behavioral measures of anxiety were assessed. Treatment was chosen by patients: either 12 weeks of CBT alone or CBT with sertraline.

RESULTS

All patients showed significant decrease on clinical measures from baseline and 31 were treatment responders, 8 dropped out of the study before completion of the 12-week treatment phase and 4 were deemed nonresponders after 12 weeks of treatment. Although both treatments led to significant clinical improvement, only CBT alone demonstrated a significant reduction in HR and increase in HRV.

CONCLUSIONS

Our study replicated the finding that increased HR and decreased HRV occur in PD patients. Given the evidence of cardiac risk related to HRV, CBT appears to have additional benefits beyond symptom reduction. The mechanisms of this difference between CBT and sertraline are unclear and require further study.

Co-occurrence of Insomnia and Anxiety Disorders: A Review of the Literature

Insomnia and anxiety disorders are highly prevalent and are associated with significant impairment and disability. There is evidence that insomnia and anxiety disorders commonly co-occur, in addition to both being highly comorbid with major depressive disorder. Thus, it is important for health care providers to be familiar with the literature in this area. Therefore, the purpose of this review was to examine the empirical literature on the co-occurrence of insomnia and anxiety disorders, as well as discuss the clinical and research implications of the findings. Studies were identified through PubMed and PsycINFO searches (1975-2007) and a bibliographic review of published articles. The results from this literature review suggest that certain anxiety disorders, such as panic disorder and generalized anxiety disorder, are clearly associated with symptoms of insomnia (eg, delayed sleep onset, restless sleep). Although there are some discrepancies in the literature, the findings suggest that individuals with posttraumatic stress disorder also experience significant sleep problems (eg, middle-of-the-night insomnia, poor sleep quality, nightmares), and the presence of such problems during the early posttrauma period predicts later development of the disorder. Few empirical studies examine sleep in other anxiety disorders, and the majority of studies on insomnia and anxiety disorders in general have not examined the effects of comorbid major depressive disorder, indicating a need for additional research. Overall, the findings highlight the importance of screening for and treating anxiety symptoms when a patient presents with symptoms of insomnia and vice versa. Clearly, treatment development work on interventions that address co-occurring insomnia and anxiety disorders is greatly needed.

Sleep-based heart period variability in panic disorder with and without nocturnal panic attacks

In this paper, we investigated ambulatory sleep heart period variability in panic disorder participants with nocturnal panic (NP) compared to daytime panic attacks only. A time-derived measure of heart period variability (HPV) during sleep was significantly reduced in the NP group (n=32) relative to the daytime panic (n=17) and nonanxious (n=17) control groups. Consistent with previous work, NP participants also reported greater fear of relaxation and sleep than daytime panic and control groups. Based on a neurovisceral model of attention [Thayer, J. F., & Lane, R. D. (2000). A model of neurovisceral integration in emotion regulation and dysregulation. Journal of Affective Disorders, 61, 210-216] that predicts that decreased HPV is related to disregulated behavioral adaptation, we hypothesized that HPV measured during sleep would be most reduced in NP participants. These findings indicate that HPV is related to nocturnal panic disorder insofar as it is measured during sleep.

Axis I and II comorbidities in subjects with and without nocturnal panic

Our purpose in this study was to compare the prevalence and pattern of Axis I and II comorbidities between patients with and without nocturnal panic (NP) attacks. One hundred and sixteen subjects with panic disorder (PD; according to DSM-IV criteria) were included: We assessed Axis I and II comorbidities using the Structured Clinical Interview for DSM-IV Axis I and II disorders, respectively. Of the sample, 27.6% of subjects had recurrent nocturnal panic attacks (NP group). Subjects with NP did not differ from those without in any sociodemographic or clinical characteristics. In the sample (94 subjects), 81% had at least one lifetime comorbid Axis I disorder, without significant differences between subjects with and without nocturnal panic even when considering comorbidity rates for single disorders; a trend toward significance was found for anorexia nervosa and somatization disorder, which both were more frequent among subjects with NP. Concerning Axis II disorders, 49.1% of the sample (57 subjects) met the criteria for at least one personality disorder, without significant differences between patients with and without NP. No significant differences were detected in comorbidity rates for any single Axis II personality disorder. Personality might play a relevant role in influencing treatment approaches to PD, but it does not appear to be a differential focus of concern in patients with compared to those without NP.

Sleep and anxiety disorders

Sleep disturbances commonly are associated with anxiety disorders, in particular generalized anxiety disorder, panic disorder, and posttraumatic stress disorder. Sleep loss may exacerbate and contribute to relapse of these conditions. Core features of panic disorder and posttraumatic stress disorder occur in relation to sleep (sleep panic attacks or re-experiencing nightmares). Investigation of sleep in anxiety disorders provides clues to mechanisms of arousal regulation relevant to insomnia and pathologic anxiety. Established treatments for anxiety disorders and insomnia have many overlapping components; however, optimal sequencing and integration of the approaches remain under-investigated.

Paroxysmal Motor Disorders of Sleep: The Clinical Spectrum and Differentiation from Epilepsy

The diagnosis of paroxysmal events in sleep represents a significant challenge for the clinician, with the distinction of nocturnal epilepsy from nonepileptic sleep disorders often the primary concern. Diagnostic error or uncertainty is not uncommon in this situation, particularly with respect to nocturnal frontal lobe epilepsy (NFLE), which has a variable and often unusual presentation. Such errors can be minimized if the range of nonepileptic disorders with motor activity in sleep is fully appreciated. Here we review these disorders, before discussing the important clinical and electrographic features that allow their accurate differentiation from seizures. Particular emphasis is placed on the differentiation of nocturnal frontal lobe epilepsy from non-rapid eye movement (NREM) arousal disorders and other parasomnias. The value of recording episodes with video EEG polysomnography is discussed.

Nocturnal panic and recent life events

Recent research has hypothesized an association between traumatic events and nocturnal panic (NP). The purpose of this study was to investigate whether the onset of nocturnal panic attacks is associated with a higher frequency of and/or greater severity of stressful or traumatic life events than that of patients with panic disorders (PDs) who experience daytime panic attacks (DPs) while awake. A secondary aim was to investigate whether NP is associated with specific life events at the onset of the disorder. Our sample comprised 129 subjects with PD (DSM-IV). We investigated the number and types of stressful life events that occurred in the year prior to PD onset using a semistructured interview. Of the sample, 28.7% had recurrent nocturnal panic attacks (NP group). Subjects with and without recurrent NP did not differ on any sociodemographic or clinical characteristic. Neither the number nor type of life event distinguished those with or without NP. The subgroup of patients with PD with recurrent NP appears to represent a variant of PD with a possible increased vulnerability to conditions of diminished arousal as a trigger of panic attacks. However, the hypothesis that this vulnerability might be determined by life events that occur in the period preceding PD onset was not supported by the findings of this study.

Sleep and psychiatry

Psychiatric disorders constitute 15.4% of the disease burden in established market economies. Many psychiatric disorders are associated with sleep disturbances, and the relationship is often bidirectional. This paper reviews the prevalence of various psychiatric disorders, their clinical presentation, and their association with sleep disorders. Among the psychiatric disorders reviewed are affective disorders, psychosis, anxiety disorders (including posttraumatic stress disorder), substance abuse disorders, eating disorders, and attention deficit/hyperactivity disorders. The spectrum of associated sleep disorders includes insomnia, hypersomnia, nocturnal panic, sleep paralysis, hypnagogic hallucinations, restless legs/periodic limb movements of sleep, obstructive sleep apnea, and parasomnias. The effects on sleep of various psychotropic medications utilized to treat the above psychiatric disorders are summarized.

Arterial pressure and heart rate increase during REM sleep in adenosine A2A-receptor knockout mice, but not in wild-type mice

Rapid eye movement (REM)-sleep related changes in arterial pressure (AP) and heart rate (HR) were observed in homozygous and heterozygous adenosine A(2A) receptor (A2AR) knockout (KO) mice, and the corresponding wild-type mice. During REM sleep, the mean AP (MAP) and HR were clearly increased in the homozygous A2AR KO mice, while, in the wild-type mice, they were decreased or maintained at the same level. Neither homozygous nor heterozygous A2AR KO mice showed significant difference in diurnal pattern and the hourly values of MAP and HR compared to the wild-type mice. From these findings, it is likely that the adenosine A2AR is involved in autonomic regulation during REM sleep.

Sleep in patients with neurologic and psychiatric disorders

Given the widely recognized association between many neurologic and psychiatric disorders and significant sleep disturbances, the International Classification of Sleep Disorders Diagnostic and Coding Manual recognizes "Sleep Disorders Associated with Mental, Neurologic, or Other Medical Disorders" as one of four major classification categories. Such sleep disturbances may exacerbate symptoms of the underlying neurologic or psychiatric disorder or produce further adverse medical, behavioral, or psychosocial consequences. Therefore, adequate assessment and recognition of sleep disturbances in these populations is essential. This article includes a summary of neurologic systems influencing sleep that may be affected by neurologic and psychiatric disorders, followed by a brief review of sleep disturbances associated with many common neurologic and psychiatric disorders.

Sleep disturbance in anxiety disorders

Many patients suffering from the majority of anxiety disorders complain about their sleep by reporting difficulties in initiating and maintaining it. Polysomnographic studies have shown that, in comparison to normal subjects, the sleep of patients with panic disorder is characterized by longer sleep latency, increased time awake and reduced sleep efficiency. Sleep architecture is normal and there are no significant changes in REM sleep measures. Nocturnal panic attacks are non-REM-related events and occur without an obvious trigger in 18-45% of panic disorder patients. Regarding generalized anxiety disorder, the patients complain of 'trouble sleeping' in 60-70%, while polysomnography has shown increased sleep latency and decreased sleep continuity measures. The findings in REM sleep and sleep architecture generally do not show any aberration to exist. In patients with obsessive-compulsive disorder (OCD) and post-traumatic stress disorder (PTSD), results from the sleep laboratory do not seem to support the subjective complaints of poor sleep. The early reports of shortened REM latency in OCD could not be replicated by recent studies. A dysregulation of the REM sleep control system has been reported for patients with PTSD. Finally, no significant differences were found in all sleep parameters between social phobia patients and controls.

Cognitive behavior therapy for chronic insomnia occurring within the context of medical and psychiatric disorders

Insomnia is a pervasive problem for many patients suffering from medical and psychiatric conditions. Even when the comorbid disorders are successfully treated, insomnia often fails to remit. In addition to compromising quality of life, untreated insomnia may also aggravate and complicate recovery from the comorbid disease. Cognitive behavior therapy for insomnia (CBT-I) has an established efficacy for primary insomnia, but less is known about its efficacy for insomnia occurring in the context of medical and psychiatric conditions. The purpose of this article is to present a rationale for using CBT-I in medical and psychiatric disorders, review the extant outcome literature, highlight considerations for adapting CBT-I procedures in specific populations, and suggest directions for future research. Outcome studies were identified for CBT-I in mixed medical and psychiatric conditions, cancer, chronic pain, HIV, depression, posttraumatic stress disorder, and alcoholism. Other disorders discussed include: bipolar disorder, eating disorders, generalized anxiety, and obsessive compulsive disorder. The available data demonstrate moderate to large treatment effects (Cohen's d, range=0.35-2.2) and indicate that CBT-I is a promising treatment for individuals with medical and psychiatric comorbidity. Although the literature reviewed here is limited by a paucity of randomized, controlled studies, the available data suggest that by improving sleep, CBT-I might also indirectly improve medical and psychological endpoints. This review underscores the need for future research to test the efficacy of adaptations of CBT-I to disease specific conditions and symptoms.

Sleep complaints in panic disorder patients

Patients with anxiety disorders often report difficulty sleeping. The present study assesses the prevalence of sleep complaints in panic disorder (PD) patients, compares them with sleep complaints in a normal population, and investigates the role of comorbid depression and nocturnal panic attacks in sleep complaints in the PD patients. Seventy PD patients and 70 healthy controls were asked about their subjective sleep characteristics by means of the Sleep-Wake Experience List, which assesses sleep/arousal complaints over a 24-hour period. Sixty-seven percent of the PD patients reported sleep complaints, compared with 20% of the controls. Eighty-six percent of the depressed PD patients and 59% of the nondepressed had sleep difficulties; 77% of the PD patients with nocturnal panic attacks reported sleep complaints, versus 53% of the PD patients without nocturnal panic. It is concluded that PD patients demonstrate a higher prevalence of sleep complaints than normal controls; this can only partly be explained by comorbid depression, and cannot be explained by the presence of nocturnal panic attacks.

Assessment and treatment of nocturnal panic attacks

Nocturnal panic (NP), waking from sleep in a state of panic, is a common occurrence among patients with panic disorder, with 44-71% reporting at least one such attack. NP is a non-REM event that is distinct from sleep terrors, sleep apnea, nightmares or dream-induced arousals. This review outlines recent advances in the characterization of NP, as well as current approaches to the assessment and treatment of NP. In contrast to earlier work, more recent studies suggest that patients with NP do not differ from patients without NP on sleep architecture, sleep physiology, self-reported sleep quality and severity of panic disorder. However, more precise measurement of physiological precipitants and features is warranted. Assessment of NP focuses on ruling out other explanations for NP, with differential diagnosis based on interviews, sleep polysomnography and ambulatory recording of sleep. Psychological treatment (cognitive-behavioral therapy) targets misappraisals of anxiety sensations, hyperventilatory response, and conditioned reactions to internal, physical cues. Recent evidence supports the efficacy of this approach, however, controlled studies on pharmacological agents in the treatment of NP are lacking. Research is needed to examine the effects of combined cognitive-behavioral therapy and medications, compared to medication alone in the treatment of NP.

Sleep disturbances in patients treated for panic disorder

BACKGROUND AND PURPOSE

Disturbed night sleep is a common complaint of patients with panic disorder. The aim of the present study was to demonstrate whether the sleep disturbances can be successively influenced by the standard therapy for treating panic disorder.

PATIENTS AND METHODS

Psychiatric examinations of 20 outpatients with panic disorder were supplemented with a study of sleep quality using standardised interviews, sleep logs and polysomnographic recordings.

RESULTS

A statistical comparison of data showed that reduced anxiety after successful treatment of panic disorder was not necessarily followed by improved sleep parameters.

CONCLUSION

The results suggest that the conventional therapy applied to these patients is not sufficient to treat the co-existing insomnia. Consequently, it seems to be of importance to supplement the treatment of panic disorders with specific treatment of the sleep disturbance.

Correlates of therapeutic response in panic disorder presenting with palpitations: heart rate variability, sleep, and placebo effect

OBJECTIVE

To examine the correlates of therapeutic response of patients with panic disorder presenting with palpitations, we hypothesized that therapeutic response would correlate with heart rate variability (HRV) and sleep measures.

METHODS

After a 1-week placebo washout, 27 patients free of structural heart disease and not on cardioactive drugs were randomized in a double-blinded fashion to 4 weeks of treatment with clonazepam (a known antipanic agent) or placebo. We performed standard sleep measures and recorded HRV from 24-hour Holter acquisitions at baseline and end of study. We defined response to therapy as a 50% improvement in the Hamilton Anxiety Rating Scale (HARS) score, confirmed by questionnaires and reaction to sodium lactate infusion.

RESULTS

There were 12 responders and 15 nonresponders. Normalization of sleep pattern (including less stage 1 and rapid eye movement [REM] sleep) was observed in both drug and placebo responders (P = 0.011 and P = 0.05, respectively) and in placebo responders alone, compared with nonresponders (P = 0.006 and P = 0.013, respectively). Placebo responders were more likely to show less depression, but even after we controlled for depression, main sleep effects remained. None of the HRV measures correlated with response, but compared with placebo, clonazepam led to a decrease in all the time and frequency domain measures of HRV (all P < 0.05).

CONCLUSIONS

Central mechanisms are related to the therapeutic response of patients with panic disorder presenting with palpitations, but this does not directly correlate with HRV. Larger and longer studies may allow objective explanations of placebo response in panic disorder.

Increased sympathetic response to standing in panic disorder

Although autonomic function has been investigated in panic disorder (PD), previous studies have not used non-invasive beat by beat blood pressure (BP) monitoring to assess the rapid dynamics of BP during autonomic reflex tests. The hypothesis of the current study was that patients with PD would show increased cardiovascular sympathetic reactivity compared with healthy or anxious controls, as assessed by the initial overshoot of diastolic BP during the immediate response to standing. Patients with PD (n=56), social phobia (n=28) and healthy volunteers (n=56) were tested using finger photoplethysmography during an orthostatic challenge. Panic disorder patients showed an increased BP overshoot compared with both control groups. Moreover, in a preliminary assessment of selective serotonin reuptake inhibitor treatment effects, the BP overshoot was significantly reduced towards normal values. These findings are consistent with recent evidence for increased sympathetic baroreflex function in PD and may be relevant to the pathophysiology of the disorder.

Correlation between electroencephalography and heart rate variability during sleep

It is known that autonomic nervous activities change in correspondence with sleep stages. However, the characteristics of continuous fluctuations in nocturnal autonomic nerve tone have not been clarified in detail. The study aimed to determine the possible correlation between the electroencephalogram (EEG) and autonomic nervous activities, and to clarify in detail the nocturnal fluctuations in autonomic nerve activities. Overnight EEGs and electrocardiograms of seven healthy males were obtained. These EEGs were analyzed by fast Fourier transformation algorithm to extract delta, sigma and beta power. Heart rate and heart rate variability (HRV) were calculated in consecutive 5-min epochs. The HRV indices of low frequency (LF), high frequency (HF) and LF/HF ratio were calculated from the spectral analysis of R-R intervals. The sleep stages were manually scored according to Rechtschaffen and Kales' criteria. Low frequency and LF/HF were significantly lower during non-rapid eye movement (NREM) than REM, and were lower in stages 3 and 4 than in stages 1 and 2. Furthermore, delta EEG showed inverse correlations with LF (r = - 0.44, P < 0.001) and LF/HF (r = - 0.41, P < 0.001). In contrast, HF differed neither between REM and NREM nor among NREM sleep stages. Detailed analysis revealed that correlation was evident from the first to third NREM, but not in the fourth and fifth NREM. Delta EEG power showed negative correlations with LF and LF/HF, suggesting that sympathetic nervous activities continuously fluctuate in accordance with sleep deepening and lightening.

Psychogenic, nonepileptic seizures associated with video-EEG-verified sleep

PURPOSE

Nonepileptic seizures (NES) are expressions of a psychiatric disease state, usually conversion disorder, that mimic epileptic seizures (ES) but are not associated with the neurophysiologic changes of epilepsy. Conversion has not been demonstrated to emerge from the sleeping state. Emergence out of sleep is usually considered a virtual exclusion criterion for NES, signifying the presence instead of ES. We sought to test this hypothesis.

METHODS

We retrospectively reviewed the video-EEG of all patients admitted to our epilepsy unit over a 3-year period, who were suspected of manifesting NES. We examined the relation between NES and the patients' sleep/wake state in this cohort. Two epileptologists blindly reviewed an intermixture of cases suspected to represent NES emerging out of sleep, together with control cases. Classification of each case was made independently.

RESULTS

We found that in a small minority of patients (<1%), NES began either while the patient was sleeping, or within several seconds of arousal, well before a plan to simulate a seizure could likely have been formulated in the wakeful state.

CONCLUSIONS

In some cases, NES are not the product of the awake mind, but rather represent a psychiatric condition that can be manifest in sleep.

Schlafstörungen bei kinder- und jugendpsychiatrischen Erkrankungen

Zusammenfassung: Schlafstörungen als Symptom zahlreicher kinder- und jugendpsychiatrischer Störungsbilder komplizieren häufig den Verlauf und die Behandlung der Grunderkrankung. Organische Störungen wie die Narkolepsie oder das Kleine-Levin-Syndrom können zu differentialdiagnostischen Schwierigkeiten und Fehleinschätzungen führen. Unklar ist, ob spezifische Veränderungen der Schlafarchitektur bereits im Kindes- und Jugendalter bestehen und damit als biologischer Trait-Marker für psychiatrische Erkrankungen zu verstehen sind. Während für das Erwachsenenalter die Bedeutung von Schlafstörungen vor allem für die Entwicklung späterer depressiver Störungen belegt werden konnte, ist derzeit offen, ob es sich bei persistierenden Schlafstörungen im Kindesalter um Vulnerabilitätsmarker für psychiatrische Erkrankungen handelt. In der vorliegenden Literaturübersicht sollen Wechselwirkungen zwischen Schlafstörung und psychischer Störung aufgezeigt und die Bedeutung der Berücksichtigung von Schlafstörungen für Diagnostik und Therapie kinder- und jugendpsychiatrischer Störungsbilder unterstrichen werden.