The European Insomnia Guideline: An update on the diagnosis and treatment of insomnia 2023.

Progress in the field of insomnia since 2017 necessitated this update of the European Insomnia Guideline. Recommendations for the diagnostic procedure for insomnia and its comorbidities are: clinical interview (encompassing sleep and medical history); the use of sleep questionnaires and diaries (and physical examination and additional measures where indicated) (A). Actigraphy is not recommended for the routine evaluation of insomnia (C), but may be useful for differential-diagnostic purposes (A). Polysomnography should be used to evaluate other sleep disorders if suspected (i.e. periodic limb movement disorder, sleep-related breathing disorders, etc.), treatment-resistant insomnia (A) and for other indications (B). Cognitive-behavioural therapy for insomnia is recommended as the first-line treatment for chronic insomnia in adults of any age (including patients with comorbidities), either applied in-person or digitally (A). When cognitive-behavioural therapy for insomnia is not sufficiently effective, a pharmacological intervention can be offered (A). Benzodiazepines (A), benzodiazepine receptor agonists (A), daridorexant (A) and low-dose sedating antidepressants (B) can be used for the short-term treatment of insomnia (≤ 4 weeks). Longer-term treatment with these substances may be initiated in some cases, considering advantages and disadvantages (B). Orexin receptor antagonists can be used for periods of up to 3 months or longer in some cases (A). Prolonged-release melatonin can be used for up to 3 months in patients ≥ 55 years (B). Antihistaminergic drugs, antipsychotics, fast-release melatonin, ramelteon and phytotherapeutics are not recommended for insomnia treatment (A). Light therapy and exercise interventions may be useful as adjunct therapies to cognitive-behavioural therapy for insomnia (B).

Treating Insomnia with High Risk of Depression Using Therapist-Guided Digital Cognitive, Behavioral, and Circadian Rhythm Support Interventions to Prevent Worsening of Depressive Symptoms: A Randomized Controlled Trial.

INTRODUCTION: The global disease burden of major depressive disorder urgently requires prevention in high-risk individuals, such as recently discovered insomnia subtypes. Previous studies targeting insomnia with fully automated eHealth interventions to prevent depression are inconclusive: dropout was high and likely biased, and depressive symptoms in untreated participants on average improved rather than worsened. OBJECTIVE: This randomized controlled trial aimed to efficiently prevent the worsening of depressive symptoms by selecting insomnia subtypes at high risk of depression for internet-based circadian rhythm support (CRS), cognitive behavioral therapy for insomnia (CBT-I), or their combination (CBT-I+CRS), with online therapist guidance to promote adherence. METHODS: Participants with an insomnia disorder subtype conveying an increased risk of depression (n = 132) were randomized to no treatment (NT), CRS, CBT-I, or CBT-I+CRS. The Inventory of Depressive Symptomatology - Self Report (IDS-SR) was self-administered at baseline and at four follow-ups spanning 1 year. RESULTS: Without treatment, depressive symptoms indeed worsened (d = 0.28, p = 0.041) in high-risk insomnia, but not in a reference group with low-risk insomnia. Therapist-guided CBT-I and CBT-I+CRS reduced IDS-SR ratings across all follow-up assessments (respectively, d = -0.80, p = 0.001; d = -0.95, p < 0.001). Only CBT-I+CRS reduced the 1-year incidence of clinically meaningful worsening (p = 0.002). Dropout during therapist-guided interventions was very low (8%) compared to previous automated interventions (57-62%). CONCLUSIONS: The findings tentatively suggest that the efficiency of population-wide preventive strategies could benefit from the possibility to select insomnia subtypes at high risk of developing depression for therapist-guided digital CBT-I+CRS. This treatment may provide effective long-term prevention of worsening of depressive symptoms. TRIAL REGISTRATION: the Netherlands Trial Register (NL7359).

Cost-effectiveness of Guided Internet-Delivered Cognitive Behavioral Therapy in Comparison with Care-as-Usual for Patients with Insomnia in General Practice.

STUDY OBJECTIVES: Clinical guidelines recommend cognitive-behavioral therapy for insomnia (CBT-I) as first-line treatment. However, provision of CBT-I is limited due to insufficient time and expertise. Internet-delivered CBT-I might bridge this gap. This study aimed to estimate the cost-effectiveness of guided, internet-delivered CBT-I (i-Sleep) compared to care-as-usual for insomnia patients in general practice over 26 weeks from a societal perspective. METHODS: Primary outcomes were the Insomnia Severity Index (ISI, continuous score and clinically relevant response), and Quality-Adjusted Life Years (QALYs). Societal costs were assessed at baseline, and at 8 and 26 weeks. Missing data were imputed using multiple imputation. Statistical uncertainty around cost and effect differences was estimated using bootstrapping, and presented in cost-effectiveness planes and acceptability curves. RESULTS: The difference in societal costs between i-Sleep and care-as-usual was not statistically significant (-€318; 95% CI -1282 to 645). Cost-effectiveness analyses revealed a 95% probability of i-Sleep being cost-effective compared to care-as-usual at ceiling ratios of €450/extra point of improvement in ISI score and €7,000/additional response to treatment, respectively. Cost-utility analysis showed a 67% probability of cost-effectiveness for i-Sleep compared to care-as-usual at a ceiling ratio of 20,000 €/QALY gained. CONCLUSIONS: The internet-delivered intervention may be considered cost-effective for insomnia severity in comparison with care-as-usual from the societal perspective. However, the improvement in insomnia severity symptoms did not result in similar improvements in QALYs.

Telephone-guided imagery rehearsal therapy for nightmares: Efficacy and mediator of change.

The currently best-supported psychological treatment for nightmares is imagery rehearsal therapy. The problem, however, is that not enough trained practitioners are available to offer this treatment. A possible solution is to conduct imagery rehearsal therapy in a guided self-help format. In the current study, 70 participants with nightmares according to the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders were randomized to either telephone-guided imagery rehearsal therapy (n = 36) or a wait-list condition (n = 34). Participants in the imagery rehearsal therapy condition received three sessions over the course of 5 weeks. Every treatment session was followed by telephone support delivered by postgraduate students. Participants who received imagery rehearsal therapy showed larger improvements on nightmare frequency (d = 1.03; p < .05), nightmare distress (d = 0.75; p < .05) and insomnia severity (d = 1.12; p < .001) compared with the participants in the wait-list condition. The effects were sustained at 3- and 6-month follow-up. No significant effects were observed on the number of nights with nightmares per week, anxiety and depression. In line with earlier reports, the treatment effect was mediated by the increase of mastery at mid-treatment, underlining the mechanistic value of mastery in imagery rehearsal therapy. The present study demonstrates that it is possible to deliver imagery rehearsal therapy in a self-help format supported by unexperienced therapists and with relatively little time investment. This opens possibilities in terms of cost-effectiveness, scalability and dissemination of imagery rehearsal therapy in the treatment of nightmares.

Nurse-Guided Internet-Delivered Cognitive Behavioral Therapy for Insomnia in General Practice: Results from a Pragmatic Randomized Clinical Trial.

INTRODUCTION: Guidelines recommend cognitive behavioral therapy for insomnia (CBT-I) as the first line of treatment for insomnia in general practice, but CBT-I is rarely available. Nurse-guided Internet-delivered CBT-I might be a solution to improve access to care. OBJECTIVE: We aimed to determine the effectiveness of nurse-guided Internet-delivered CBT-I (I-CBT-I) on insomnia severity experienced by patients in general practice. METHODS: Nurse-guided I-CBT-I ("i-Sleep") was compared to care-as-usual (and I-CBT-I after 6 months) in 15 participating general practices among 134 patients (≥18 years old) with clinical insomnia symptoms. Assessments took place at 8, 26 and 52 weeks. Primary outcome was self-reported insomnia severity (Insomnia Severity Index) at 8 weeks. Secondary outcomes were sleep diary indices, depression and anxiety symptoms (Hospital Anxiety and Depression Scale), fatigue, daytime consequences of insomnia, sleep medication and adverse events. RESULTS: Two thirds of the 69 intervention patients (n = 47; 68%) completed the whole intervention. At the posttest examination, there were large significant effects for insomnia severity (Cohen's d =1.66), several sleep diary variables (wake after sleep onset, number of awakenings, terminal wakefulness, sleep efficiency, sleep quality) and depression. At 26 weeks there were still significant effects on insomnia severity (d = 1.02) and on total sleep time and sleep efficiency. No significant effects were observed for anxiety, fatigue, daily functioning or sleep medication. No adverse events were reported. CONCLUSIONS: Nurse-guided I-CBT-I effectively reduces insomnia severity among general practice patients. I-CBT-I enables general practitioners to offer effective insomnia care in accordance with the clinical guidelines.

Aetiology and treatment of nightmare disorder: State of the art and future perspectives.

This consensus paper provides an overview of the state of the art in research on the aetiology and treatment of nightmare disorder and outlines further perspectives on these issues. It presents a definition of nightmares and nightmare disorder followed by epidemiological findings, and then explains existing models of nightmare aetiology in traumatized and non-traumatized individuals. Chronic nightmares develop through the interaction of elevated hyperarousal and impaired fear extinction. This interplay is assumed to be facilitated by trait affect distress elicited by traumatic experiences, early childhood adversity and trait susceptibility, as well as by elevated thought suppression and potentially sleep-disordered breathing. Accordingly, different treatment options for nightmares focus on their meaning, on the chronic repetition of the nightmare or on maladaptive beliefs. Clinically, knowledge of healthcare providers about nightmare disorder and the delivery of evidence-based interventions in the healthcare system is discussed. Based on these findings, we highlight some future perspectives and potential further developments of nightmare treatments and research into nightmare aetiology.

Digital Delivery of Cognitive Behavioral Therapy for Insomnia.

PURPOSE OF REVIEW: Digital cognitive behavioral therapy (dCBT) has been available for over a decade. We reviewed the evidence that accumulated over the past 5 years and discuss the implications for introducing dCBT into standard healthcare. RECENT FINDINGS: Studies have consistently supported the use of dCBT to treat insomnia. Evidence is now demonstrating large short-term effects and smaller long-term effects up to 1.5 years after treatment across populations with various co-occurring health problems. The effects also extend into a range of psychological well-being factors. Mediators and moderators have been studied to understand mechanisms and create new opportunities to enhance effectiveness and reduce dropout. Incorporating personalized guidance in dCBT may further enhance effectiveness. The evidence for dCBT for insomnia is strong and suggests that dCBT is ready for application in standard healthcare. Further research, digital innovation, and development of effective implementation methods are required to ensure dCBT fulfills its potential.

When Thinking Impairs Sleep: Trait, Daytime and Nighttime Repetitive Thinking in Insomnia.

We performed two studies in individuals with sleep problems to investigate trait, daytime, and nighttime repetitive thinking as risk factors for insomnia. In Study 1, 139 participants completed questionnaires on worry, rumination, insomnia, anxiety, depression, and a sleep diary. Trait rumination and trait worry were not associated with sleep impairment. In Study 2, 64 participants completed similar measures and a daytime and nighttime sleep-related worry diary. Only nighttime sleep-related worry was consistently associated with sleep impairment. Overall, results indicate that nighttime sleep-related worry is important in the maintenance of insomnia, whereas effects of trait and daytime repetitive thinking are more benign. Treatment for insomnia can potentially be improved by focusing more on nighttime sleep-related worry.

Mobile Phone-Delivered Cognitive Behavioral Therapy for Insomnia: A Randomized Waitlist Controlled Trial.

BACKGROUND: This study is one of the first randomized controlled trials investigating cognitive behavioral therapy for insomnia (CBT-I) delivered by a fully automated mobile phone app. Such an app can potentially increase the accessibility of insomnia treatment for the 10% of people who have insomnia. OBJECTIVE: The objective of our study was to investigate the efficacy of CBT-I delivered via the Sleepcare mobile phone app, compared with a waitlist control group, in a randomized controlled trial. METHODS: We recruited participants in the Netherlands with relatively mild insomnia disorder. After answering an online pretest questionnaire, they were randomly assigned to the app (n=74) or the waitlist condition (n=77). The app packaged a sleep diary, a relaxation exercise, sleep restriction exercise, and sleep hygiene and education. The app was fully automated and adjusted itself to a participant's progress. Program duration was 6 to 7 weeks, after which participants received posttest measurements and a 3-month follow-up. The participants in the waitlist condition received the app after they completed the posttest questionnaire. The measurements consisted of questionnaires and 7-day online diaries. The questionnaires measured insomnia severity, dysfunctional beliefs about sleep, and anxiety and depression symptoms. The diary measured sleep variables such as sleep efficiency. We performed multilevel analyses to study the interaction effects between time and condition. RESULTS: The results showed significant interaction effects (P<.01) favoring the app condition on the primary outcome measures of insomnia severity (d=-0.66) and sleep efficiency (d=0.71). Overall, these improvements were also retained in a 3-month follow-up. CONCLUSIONS: This study demonstrated the efficacy of a fully automated mobile phone app in the treatment of relatively mild insomnia. The effects were in the range of what is found for Web-based treatment in general. This supports the applicability of such technical tools in the treatment of insomnia. Future work should examine the generalizability to a more diverse population. Furthermore, the separate components of such an app should be investigated. It remains to be seen how this app can best be integrated into the current health regimens. TRIAL REGISTRATION: Netherlands Trial Register: NTR5560; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=5560 (Archived by WebCite at http://www.webcitation.org/6noLaUdJ4).

Nightmare Disorder, Psychopathology Levels, and Coping in a Diverse Psychiatric Sample.

OBJECTIVE: Nightmares are associated with psychopathology and impaired coping in the general population. However, little is known about this association in a psychiatric population. In this study, we investigate whether patients with diverse psychiatric disorders have increased symptomatology and different coping styles if they suffer from comorbid nightmare disorder. METHOD: Participants were 498 patients with diverse moderate to severe psychiatric disorders. As part of a standard assessment procedure, they filled out questionnaires regarding nightmares, psychopathology, personality pathology, and coping. RESULTS: A multivariate analysis of covariance and post hoc tests showed that patients with nightmare disorder scored higher on psychopathology (ηp2 = .03; p = .001) and personality pathology (ηp2 = .01-.03; p < .05). No significant differences were found with regards to coping strategies. CONCLUSION: Nightmare disorder is associated with higher levels of psychopathology and personality pathology in a sample of patients with diverse psychiatric disorders.

Cost-effectiveness of i-Sleep, a guided online CBT intervention, for patients with insomnia in general practice: protocol of a pragmatic randomized controlled trial.

BACKGROUND: Insomnia is a highly prevalent disorder causing clinically significant distress and impairment. Furthermore, insomnia is associated with high societal and individual costs. Although cognitive behavioural treatment for insomnia (CBT-I) is the preferred treatment, it is not used often. Offering CBT-I in an online format may increase access. Many studies have shown that online CBT for insomnia is effective. However, these studies have all been performed in general population samples recruited through media. This protocol article presents the design of a study aimed at establishing feasibility, effectiveness and cost-effectiveness of a guided online intervention (i-Sleep) for patients suffering from insomnia that seek help from their general practitioner as compared to care-as-usual. METHODS/DESIGN: In a pragmatic randomized controlled trial, adult patients with insomnia disorder recruited through general practices are randomized to a 5-session guided online treatment, which is called "i-Sleep", or to care-as-usual. Patients in the care-as-usual condition will be offered i-Sleep 6 months after inclusion. An ancillary clinician, known as the psychological well-being practitioner who works in the GP practice (PWP; in Dutch: POH-GGZ), will offer online support after every session. Our aim is to recruit one hundred and sixty patients. Questionnaires, a sleep diary and wrist actigraphy will be administered at baseline, post intervention (at 8 weeks), and at 6 months and 12 months follow-up. Effectiveness will be established using insomnia severity as the main outcome. Cost-effectiveness and cost-utility (using costs per quality adjusted life year (QALY) as outcome) will be conducted from a societal perspective. Secondary measures are: sleep diary, daytime consequences, fatigue, work and social adjustment, anxiety, alcohol use, depression and quality of life. DISCUSSION: The results of this trial will help establish whether online CBT-I is (cost-) effective and feasible in general practice as compared to care-as-usual. If it is, then quality of care might be increased because implementation of i-Sleep makes it easier to adhere to insomnia guidelines. Strengths and limitations are discussed. TRIAL REGISTRATION: Netherlands Trial register NTR 5202 (registered April 17(st) 2015).

Adherence to Technology-Mediated Insomnia Treatment: A Meta-Analysis, Interviews, and Focus Groups.

BACKGROUND: Several technologies have been proposed to support the reduction of insomnia complaints. A user-centered assessment of these technologies could provide insight into underlying factors related to treatment adherence. OBJECTIVE: Gaining insight into adherence to technology-mediated insomnia treatment as a solid base for improving those adherence rates by applying adherence-enhancing strategies. METHODS: Adherence to technology-mediated sleep products was studied in three ways. First, a meta-analysis was performed to investigate adherence rates in technology-mediated insomnia therapy. Several databases were queried for technology-mediated insomnia treatments. After inclusion and exclusion steps, data from 18 studies were retrieved and aggregated to find an average adherence rate. Next, 15 semistructured interviews about sleep-support technologies were conducted to investigate perceived adherence. Lastly, several scenarios were written about the usage of a virtual sleep coach that could support adherence rates. The scenarios were discussed in six different focus groups consisting of potential users (n=15), sleep experts (n=7), and coaches (n=9). RESULTS: From the meta-analysis, average treatment adherence appeared to be approximately 52% (95% CI 43%-61%) for technology-mediated insomnia treatments. This means that, on average, half of the treatment exercises were not executed, suggesting there is a substantial need for adherence and room for improvement in this area. However, the users in the interviews believed they adhered quite well to their sleep products. Users mentioned relying on personal commitment (ie, willpower) for therapy adherence. Participants of the focus groups reconfirmed their belief in the effectiveness of personal commitment, which they regarded as more effective than adherence-enhancing strategies. CONCLUSIONS: Although adherence rates for insomnia interventions indicate extensive room for improvement, users might not consider adherence to be a problem; they believe willpower to be an effective adherence strategy. A virtual coach should be able to cope with this "adherence bias" and persuade users to accept adherence-enhancing strategies, such as reminders, compliments, and community building.

Sleep-Related Safety Behaviors and Dysfunctional Beliefs Mediate the Efficacy of Online CBT for Insomnia: A Randomized Controlled Trial.

Several trials have demonstrated the efficacy of online cognitive behavioral therapy (CBT) for insomnia. However, few studies have examined putative mechanisms of change based on the cognitive model of insomnia. Identification of modifiable mechanisms by which the treatment works may guide efforts to further improve the efficacy of insomnia treatment. The current study therefore has two aims: (1) to replicate the finding that online CBT is effective for insomnia and (2) to test putative mechanism of change (i.e., safety behaviors and dysfunctional beliefs). Accordingly, we conducted a randomized controlled trial in which individuals with insomnia were randomized to either online CBT for insomnia (n = 36) or a waiting-list control group (n = 27). Baseline and posttest assessments included questionnaires assessing insomnia severity, safety behaviors, dysfunctional beliefs, anxiety and depression, and a sleep diary. Three- and six-month assessments were administered to the CBT group only. Results show moderate to large statistically significant effects of the online treatment compared to the waiting list on insomnia severity, sleep measures, sleep safety behaviors, and dysfunctional beliefs. Furthermore, dysfunctional beliefs and safety behaviors mediated the effects of treatment on insomnia severity and sleep efficiency. Together, these findings corroborate the efficacy of online CBT for insomnia, and suggest that these effects were produced by changing maladaptive beliefs, as well as safety behaviors. Treatment protocols for insomnia may specifically be enhanced by more focused attention on the comprehensive fading of sleep safety behaviors, for instance through behavioral experiments.

Baseline depression levels do not affect efficacy of cognitive-behavioral self-help treatment for insomnia.

BACKGROUND: Cognitive-behavioral therapy can effectively treat insomnia (CBT-I). Randomized controlled trials have shown efficacy of self-help CBT-I, but unclear is whether excluding depressive patients boosted treatment effects. METHOD: We administered unsupported self-help CBT-I to insomnia patients with low and high depression levels. Based on the validated Centre of Epidemiological Studies-Depression (CES-D) scale, the internet-recruited sample (N = 479) was divided into three groups: low depression scores (n = 198), mild depression scores (n = 182), and high depression scores (n = 99). Follow-ups were 4 and 18 weeks after completion of the treatment. RESULTS: At 4-week follow-up, all groups had a similar amelioration on the primary sleep measures (d = 0.1-0.7; P < 0.05) and the secondary insomnia ratings (d = 1.2; P < 0.001). The only difference was that the high/mild depression groups had a steeper reduction in depression (d = 1.0-1.1; P < 0.001) and anxiety scores (d = 0.7-0.8; P < 0.001) than the low depression group (depression and anxiety: d = 0.3; P < 0.01), possibly due to floor effects in the latter group. The observed effects were sustained at the 18-week follow-up. CONCLUSIONS: This study showed that CBT-I is effective regardless of baseline depression levels. Treating the combination of insomnia and depression is an extra challenge since it is associated with increased sleep problems. These data may help us understand the relationship between insomnia and depression and indicate that self-help CBT-I may be a promising addition to regular depression treatment.

Long-term effectiveness of cognitive-behavioural self-help intervention for nightmares.

Nightmares are a prevalent disorder leading to daily impairments. Two cognitive-behavioural self-help interventions--imagery rehearsal and exposure--recently showed short-term efficacy compared to a waiting-list and a group that recorded their nightmares. This paper reports the long-term results of the imagery rehearsal (n=103) and exposure (n=95) interventions. Participants were assigned randomly to a condition after completing baseline measurements; they received a 6-week self-help intervention and completed questionnaires 4, 16 and 42 weeks after end of treatment. Initial effects on nightmare measures were almost completely sustained after 42 weeks (d=0.50-0.70); no differences were found between exposure and imagery rehearsal therapy. These results suggest that nightmares should be targeted specifically and that an internet-delivered self-help intervention seems to be a good first option in a stepped-care model.

Symptom-specific effects of cognitive therapy and behavior therapy for insomnia: A network intervention analysis.

Objective: Cognitive therapy (CT) and behavior therapy (BT) are both effective for insomnia but are expected to work via different pathways. Empirically, little is known about their symptom-specific effects. Method: This was a secondary analysis of a randomized controlled trial of online treatment for insomnia disorder (N = 219, 72.9% female, mean age = 52.5 years, SD = 13.9). Participants were randomized to CT (n = 72), BT (n = 73), or wait-list (n = 74). Network Intervention Analysis was used to investigate the symptom-specific treatment effects of CT and BT throughout treatment (wait-list was excluded from the current study). The networks included the Insomnia Severity Index items and the sleep diary-based sleep efficiency and were estimated biweekly from Week 0 until Week 10. Results: Participants in the BT condition showed symptom-specific effects compared to CT on "sleep efficiency" (Week 4-8, post-test), "difficulty maintaining sleep" (Week 4), and "dissatisfaction with sleep" (post-test). Participants in the CT showed symptom-specific effects compared to BT on "interference with daily functioning" (Week 8, post-test), "difficulty initiating sleep", "early morning awakenings," and "worry about sleep" (all post-test). Conclusions: This is the first study that observed specific differential treatment effects for BT and CT throughout the course of their treatment. These effects were more pronounced for BT than for CT and were in line with the theoretical background of these treatments. We think the embedment of the theoretical background of CT and BT in empirical data is of major importance to guide further treatment development. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Cognitive-behavioral self-help treatment for nightmares: a randomized controlled trial.

BACKGROUND: Several cognitive-behavioral techniques are effective in reducing nightmare frequency, but the therapeutic factor (e.g. cognitive restructuring, systematic desensitization) remains unclear. The aim of this study was to compare the nightmare treatments imagery rehearsal therapy (IRT), exposure, and recording (keeping a diary)--in a self-help format--with a waiting list. METHODS: Participants were recruited through a Dutch nightmare website. After completion of the baseline questionnaires, 399 participants were randomly assigned to a condition, received a 6-week self-help treatment (or were placed on the waiting list), and filled out the post-treatment measurements 11 weeks after baseline. RESULTS: Compared to the waiting list, IRT and exposure were effective in ameliorating nightmare frequency and distress, subjective sleep quality, anxiety (after imagery rehearsal), and depression (after exposure; Δd = 0.25-0.56). Compared to recording, IRT reduced nightmare frequency while exposure reduced nightmare distress (Δd = 0.20-0.30; p < 0.05). The recording condition was more effective compared to the waiting list in ameliorating nightmare frequency, nightmare distress, and subjective sleep quality (Δd = 0.19-0.28; p < 0.05). IRT had a more rapid reduction on the diary compared to exposure and recording. CONCLUSIONS: IRT and exposure appear equally effective in ameliorating nightmare complaints. Exposure to nightmare imagery may function as the crucial therapeutic factor; however, cognitive restructuring may be a useful addition to increase immediate effects.