The European Sleep Research Society (ESRS) and the European Insomnia Network (EIN) have released an update to the European Insomnia Guideline that includes new evidence on the diagnosis and treatment of insomnia since 2017.1,2 The updated guideline, intended for specialists, including sleep medicine professionals and clinicians in primary care who do not specialize in sleep medicine, was published in the Journal of Sleep Research.
The guideline authors examined relevant research published between June, 2016, and May, 2023. They graded strengths of evidence and recommendations according to a 4-tier system, granting priority to findings from meta-analyses, with secondary consideration of evidence from systematic reviews or individual randomized trials.
An Insomnia Diagnosis
Insomnia is frequently comorbid with other mental health conditions, as well as with the use of many substances. Furthermore, insomnia frequently worsens in these contexts. The guideline authors warn against the historical notion that insomnia is merely a symptom of another condition. Rather, it is an independent diagnostic entity, and an independent risk factor for other health conditions.
Since the publication of the 2017 guideline, the International Classification of Diseases, 11th Revision (ICD-11), has reorganized the main diagnostic categories of insomnia. Rather than specifying “organic” vs “nonorganic” insomnia, the current revision categorizes insomnia as chronic vs short-term. The discussions of diagnosis and treatment in this guideline reflect this change, which also brings the ICD-11 criteria into closer alignment with those of the International Classification of Sleep Disorders, 3rd Edition (ICSD-3) and the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). For readers’ reference, the guideline document displays the newest ICD and ICSD diagnostic criteria in 2 tables.
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We need data from everyday clinical practice about diagnostic procedures that are accepted and executed, treatment acceptance, adherence, attrition, side-effects and therapeutic efficacy.
Diagnostic Processes
The diagnosis of insomnia continues to be rooted in history-taking and patient report. Drawing on data from a patient sleep diary is recommended. Recently validated, shortened versions of standard questionnaires (Insomnia Severity Index, Sleep Condition Indicator) can further augment the subjective evaluation.
Actigraphy-based assessment is not mandatory. Actigraphic tools to measure sleep-time activity are increasingly available, including through inexpensive consumer products. They may be useful for identifying disruptions to patients’ sleep schedules or circadian rhythms. However, they may underestimate the severity of insomnia, could disturb sleep simply by their use, and are not strongly recommended in this update.
Polysomnography, as previously, is not useful to diagnose insomnia, but is important for assessment to rule out conditions such as periodic limb movement disorder or obstructive sleep apnea (OSA), including as possible comorbidities to insomnia.
First-Line Treatment of Insomnia
Insomnia continues to be underreported and undertreated. The guideline authors advocate for measures to increase both public and clinicians’ awareness of insomnia. They further recommend shared decision making in clinical contexts regarding treatment.
In a notable shift, a growing body of outcomes research has resolved a long-standing debate over positioning of insomnia treatments. Nonpharmacologic therapies, particularly cognitive behavioral therapy for (chronic) insomnia (CBT-I), are now recommended as first-line treatments, with medications as second-line therapy.
CBT-I
Researchers are now starting to examine several separate components of CBT-I for their relative efficacy, insights as to mechanisms of action for each, and potential side effects or contraindications.
The guideline presents recent findings on these aspects of CBT-I with respect to those components, ie, sleep hygiene education, relaxation therapy, sleep restriction therapy, stimulus control therapy, and cognitive techniques. The authors also discuss the evidence for efficacy of CBT-I in insomnia with vs without comorbidities, and for CBT-I in “self-help” guide and digital formats.
Other Psychotherapies for Insomnia
Other psychotherapies, such as mindfulness-based treatment and hypnotherapy, receive briefer treatment, as the evidence based for these remains limited. Likewise, exercise and light therapy appear to be promising adjunctive treatments, but further high-quality research is needed.
Guidance on Pharmacotherapy for Insomnia
Pharmacotherapy, as noted, is now recommended as a second-line treatment for insomnia. According to accumulated evidence across drug classes, long-term drug therapy is not routinely recommended for insomnia, as the applicable medications carry increasing risks for potential tolerance and/or dependence over time. In addition, clinical trials of many drugs studied for insomnia have lasted 12 weeks or less. Therefore, when considering continuing an insomnia medication longer than 4–12 weeks, the authors recommend that clinicians carefully consider likely benefits and risks relative to first-line therapies.
Use of DORAs for Insomnia
Both approved and off-label drugs of various classes are listed. Of particular interest is the advent of dual orexin receptor antagonists (DORAs). Daridorexant is approved by the European Medicines Agency (EMA) and by the US Food and Drug Administration (FDA). Clinical data are discussed for these drugs. Little real-world evidence on DORAs is available at this time; therefore, the authors currently recommend caution in considering them.
Other Drugs for Insomnia
Other commonly used drugs discussed in the document include benzodiazepines and benzodiazepine receptor agonists, sedating antidepressants, antipsychotics, and antihistaminergics. This guideline does not recommend the latter 2 drug classes for either short- or long-term use, in the context of insomnia. Finally, recent evidence regarding melatonin and herbal remedies is reviewed.
Final considerations on pharmacotherapy include daily vs intermittent (as-needed) dosing, and tapering of medications. Not enough evidence indicates what dosing schedules could best serve real-world patient needs, and which offer more protection against dependence.
The Future of Insomnia Research
The final section of the guideline highlights gaps in the literature, indicating needed areas of further study, including:
- Head-to-head comparisons among treatment options, such as between CBT-I and drug therapies, and between face-to-face vs digital CBT-I interventions;
- Evidence on long-term pharmacological treatment;
- More studies using validated placebo treatments;
- Outcome studies that report on remission of insomnia, as distinct from treatment response via proxy outcome variables;
- And studies of combination (eg, nonpharmacological plus pharmacological) therapies for insomnia.
The guideline authors highlight that translational research is needed. “We need data from everyday clinical practice about diagnostic procedures that are accepted and executed, treatment acceptance, adherence, attrition, side-effects and therapeutic efficacy,” they wrote.
Disclosure: Several study authors have declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of the authors’ disclosures.
