The primary objectives of this study is to evaluate the real-world effectiveness of daridorexant 50 mg in improving both subjective (self-report) and objective (actigraphic) sleep parameters in patients with chronic insomnia.

The secondary aims of this study are:

• To compare the effectiveness of daridorexant 50 mg with other guideline-recommended therapies for chronic insomnia in improving sleep parameters and sleep health.
• To identify clinical and demographic predictors of response to daridorexant 50 mg, such as age, sex, BMI, duration of insomnia, and treatment regimen (monotherapy vs. add-on).
• To monitor changes over time in the symptoms related to comorbid sleep disorders (e.g., OSA, RLS, circadian rhythm disorders) in patients treated with daridorexant 50 mg.

Insomnia affects approximately 10% of the European population and represents a significant risk factor for multiple chronic conditions, including cardiovascular diseases, depression, and type II diabetes. The latest European Guidelines for the Management of Insomnia have included daridorexant among the first-line pharmacological options for chronic insomnia. Daridorexant is a dual orexin receptor antagonist (DORA) that offers advantages over traditional hypnotics by avoiding common adverse effects such as residual daytime sedation, impaired motor coordination, and the risk of dependence.

Clinical trials have demonstrated that DORAs, including daridorexant, are effective in improving several subjective and objective sleep parameters. However, no studies to date have investigated predictors of treatment response in patients with insomnia receiving daridorexant, despite increasing awareness of the need for personalized pharmacological strategies.

In pivotal trials, daridorexant efficacy was evaluated using both subjective (patient-reported) and objective (polysomnographic) sleep outcomes. While polysomnography (PSG) is the gold standard for objective sleep evaluation, it is poorly suited for long-term, real-world monitoring due to cost, complexity, and reduced ecological validity. In contrast, actigraphy allows for non-invasive, home-based sleep-wake monitoring through wrist movement detection over multiple nights and is widely used in sleep research and clinical settings. However, no studies have employed actigraphy to assess daridorexant's real-world effectiveness, leaving a significant knowledge gap.

Another relevant aspect is the frequent co-occurrence of insomnia with other sleep disorders such as restless legs syndrome (RLS), circadian rhythm sleep-wake disorders, and obstructive sleep apnea (OSA). Evaluating the evolution of symptoms related to these comorbid sleep conditions in patients treated with daridorexant could help clarify whether its use should be expanded or restricted in certain clinical populations.

Study Objectives and Outcome Measures

Primary Objectives:

To evaluate the real-world effectiveness of daridorexant 50 mg in improving both subjective (questionnaire-based) and objective (actigraphy-based) sleep parameters in patients with chronic insomnia.

Secondary Objectives:

To compare the effectiveness of daridorexant 50 mg with other guideline-recommended therapies for chronic insomnia in improving sleep parameters and sleep health.

To identify clinical and demographic predictors of response to daridorexant 50 mg, such as age, sex, BMI, duration of insomnia, and treatment regimen (monotherapy vs. add-on).

To monitor changes over time in the symptoms related to comorbid sleep disorders (e.g., OSA, RLS, circadian rhythm disorders) in patients treated with daridorexant 50 mg.

Primary Endpoint:

This is the first prospective observational study aiming to assess the real-world effectiveness of daridorexant 50 mg in improving both subjective and actigraphic sleep parameters in patients with chronic insomnia. In addition, the study will evaluate possible changes in circadian metrics over time, with the goal of better understanding the impact of daridorexant on patients' sleep-wake rhythm under real-life conditions.

Inclusion Criteria:

• Age ≥ 18 years
• Signed informed consent form
• Diagnosis of chronic insomnia according to DSM-5 criteria, defined as:

Dissatisfaction with sleep quantity or quality, associated with one or more of the following:

Difficulty initiating sleep

Difficulty maintaining sleep (frequent awakenings or trouble returning to sleep)

Early morning awakenings with inability to return to sleep

The sleep disturbance causes clinically significant distress or impairment in social, occupational, educational, academic, or other important areas of functioning

Sleep difficulties occur despite adequate opportunity and circumstances for sleep

The insomnia is not better explained by or occurring exclusively during other sleep-wake disorders (e.g., narcolepsy, parasomnias, circadian rhythm sleep-wake disorders, breathing-related sleep disorders)

The insomnia is not attributable to the physiological effects of a substance (e.g., drug abuse or medication)

- No contraindications to daridorexant use according to the European Medicines Agency (EMA)

Exclusion Criteria:

• Pregnancy
• Breastfeeding
• Withdrawal of informed consent at any time

Adult patients (≥18 years) with a clinical diagnosis of chronic insomnia according to Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria, evaluated at the Neurology Clinic of the Azienda Ospedaliero-Universitaria Pisana (AOUP), Italy. Participants will be selected among those who receive a new prescription of daridorexant or another guideline-recommended treatment for insomnia. The population includes individuals with or without comorbid sleep disorders (e.g., RLS, OSA, circadian rhythm disorders). Both treatment-naïve patients and those previously treated with other insomnia therapies may be included, provided they meet inclusion criteria and give informed consent.