Insomnia Disorder is a common sleep disorder characterized by difficulty initiating sleep, maintaining sleep or awakening too early in the morning, significantly impairing quality of life. Chronic insomnia affects approximately 10% of the population and is closely associated not only with sleep disturbance but also with psychiatric and medical conditions such as mood disorders, anxiety, chronic pain and cardiovascular diseases. Diagnosis is often delayed or mistaken for other conditions, making accurate evaluation and timely intervention critically important.

DSM-5 Diagnostic Criteria for Insomnia Disorder

According to the American Psychiatric Association’s DSM-5, the following criteria must be met for diagnosis:

• The individual experiences at least one of the following symptoms, at least three nights per week for at least three months:
  • Difficulty initiating sleep (sleep-onset insomnia)
  • Difficulty maintaining sleep (sleep-maintenance insomnia)
  • Early-morning awakening with inability to return to sleep
• The sleep difficulty causes clinically significant distress or impairment in social, occupational or other important areas of functioning.
• The disturbance is not better explained by another sleep-wake disorder, substance use or a medical condition.
• The problem occurs despite adequate opportunity and conditions for sleep.

Symptoms of Insomnia Disorder

Insomnia disorder involves more than simply not being able to sleep. Common symptoms include:

• Feeling unrefreshed after waking
• Daytime sleepiness and impaired concentration
• Irritability, depressive mood, anxiety
• Decline in work or school performance
• Forgetfulness, attention deficits, slowed reaction time
• Psychosomatic complaints such as headaches or stomachaches

In chronic cases, symptoms may affect all areas of life, often leaving individuals feeling “constantly tired but sleepless.”

Etiology of Insomnia Disorder

Insomnia is a multifactorial disorder emerging from the interaction of biological, psychological and environmental factors. Typically, no single cause can be identified.

• Psychiatric Factors: Anxiety disorders (particularly generalized anxiety disorder), depression and posttraumatic stress disorder (PTSD) are among the most common contributors. Hyperarousal and racing thoughts at bedtime are strongly associated with insomnia.
• Physiological Factors: Conditions such as menopause, hyperthyroidism, chronic pain and gastroesophageal reflux disease increase risk. Circadian rhythm disruptions (night-shift work, jet lag) are also significant.
• Behavioral and Environmental Factors: Late-night screen use, irregular sleep schedules, caffeine and nicotine intake interfere with sleep quality.
• Genetic and Neurobiological Factors: Variations in genes regulating circadian rhythm may predispose certain individuals. Hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis has been associated with heightened arousal and insomnia (Baglioni et al., 2016, Sleep Medicine Reviews).

Risk Factors for Insomnia Disorder

Key risk factors include:

• Female gender (especially post-menopause)
• Older age
• Low socioeconomic status
• Stressful life events (bereavement, divorce, job loss)
• Chronic medical conditions
• Family history of sleep disorders

Personality traits such as perfectionism, ruminative thinking and poor stress management have also been linked to insomnia vulnerability.

Diagnosis

Diagnosis relies primarily on clinical history and evaluation. Commonly used methods include:

• Sleep Diary: Recording bedtimes, wake times, sleep onset latency and nocturnal awakenings for 1–2 weeks.
• Questionnaires: Pittsburgh Sleep Quality Index (PSQI) and Insomnia Severity Index (ISI) assess severity and functional impact.
• Polysomnography: Performed mainly to rule out comorbid sleep disorders such as sleep apnea.

It is also essential to evaluate comorbid psychiatric disorders, substance use and medication effects.

Treatment of Insomnia Disorder

Treatment should be individualized, integrating behavioral and pharmacological strategies according to severity, duration and comorbidities.

1. Cognitive Behavioral Therapy for Insomnia (CBT-I)

CBT-I is considered the first-line treatment (Qaseem et al., 2016, Annals of Internal Medicine). It targets maladaptive beliefs and behaviors related to sleep. Components include:

• Stimulus Control: The bed is reserved only for sleep and sexual activity; no watching TV or phone use.
• Relaxation Techniques: Meditation, breathing exercises, progressive muscle relaxation
• Sleep Restriction: Limiting time in bed to consolidate sleep
• Cognitive Restructuring: Challenging dysfunctional beliefs about sleep

2. Pharmacotherapy

Medications may provide short-term relief but carry risks of dependence and tolerance. Common options include:

• Benzodiazepines: Diazepam, lorazepam (short-term use)
• Non-benzodiazepine Hypnotics: Zolpidem, zopiclone (fewer side effects)
• Melatonin Agonists: Ramelteon
• Antidepressants: Low-dose trazodone or doxepin, especially when depression is comorbid

Medication should be combined with behavioral strategies for sustainable results.

3. Lifestyle Modifications and Sleep Hygiene

• Maintaining consistent sleep and wake times
• Limiting caffeine, nicotine and alcohol
• Keeping the bedroom dark, quiet and cool
• Avoiding daytime naps
• Reducing evening screen exposure

Such interventions may be highly effective, particularly in mild cases.

Impact on Daily Life

Insomnia is not confined to nighttime; it affects daytime functioning, mood and cognition. Chronic sleep deprivation can lead to:

• Reduced academic or occupational performance
• Increased risk of accidents
• Mental health issues (depression, anxiety, irritability)
• Impaired immune function

Research indicates that chronic insomnia increases risk of hypertension, diabetes and cardiovascular disease (Fernandez-Mendoza et al., 2012, Hypertension).

In conclusion, insomnia disorder significantly affects both physical and mental health but can be effectively managed with accurate diagnosis and comprehensive treatment. Sleep is not merely rest but a fundamental component of overall health. Therefore, insomnia symptoms should not be overlooked, and professional support should be sought promptly.