​Insomnia is a condition commonly seen by general practitioners in their practice, where they are in a prime position to spearhead detection, assessment and management. Find out more about how insomnia can be treated in primary care.


Insomnia is a highly prevalent disorder occurring in up to 50% of primary care patients. Two previous studies both found that about 27% of Singapore residents reported significant poor sleep.

It is linked to increased healthcare utilisation and costs, and is very often comorbid with other medical and psychiatric disorders.

Insomnia and comorbidities

Insomnia has a bidirectional link with comorbidities, where insomnia worsens the comorbidity, and the comorbidity worsens insomnia.

Insomnia is associated with an increased risk of cognitive impairment, diabetes, hypertension and mortality, whilst treating insomnia may improve the outcomes for the comorbidity.1-5


The key features of chronic insomnia are:

  • Difficulty falling asleep, maintaining sleep, or early-morning awakening
  • Impairment in important areas of functioning, despite the adequate opportunity to sleep
  • Occurring for at least three nights per week, for at least three months
Both the International Classification of Sleep Disorders – Third Edition (ICSD-3) and the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) recognise that even if insomnia is precipitated by another medical or psychiatric condition, it is important to address both disorders.

Insomnia is best viewed as a comorbid disorder that warrants separate treatment attention.3

Assessment Tools


A comprehensive clinical history is the cornerstone of assessment for insomnia.

Table 1 can be used to guide history taking, with additional considerations indicated.

The assessment can be further supplemented with screening questionnaires and tools:

  • The Insomnia Severity Index (ISI) is a short self-report seven-item questionnaire to assess the severity of insomnia.
  • A sleep diary can be useful to characterise the nature and pattern of sleep problems, and identify circadian rhythm disorders.3-4

​A Guide for Sleep History Taking​ ​


​Additional considerations

a. Chief complaint

Is it a problem of sleep initiation (falling asleep), maintenance (staying asleep), early termination, and/or unrefreshing sleep?

What is the frequency, course, severity and impact?

The impact of poor sleep can include changes to mood, cognition, performance and naps. Patients with insomnia often have difficulties taking naps, whilst patients with other sleep disorders may be sleepy and nap often.

b. Onset of issues

Age of onset, previous episodes of insomnia, premorbid sleep patterns.

How have they changed over time?

Explore if the chronology of symptoms is linked to changes in medications, medical conditions, changes to work or lifestyle, or significant life events.

c. Sleep-wake schedule

Time they go to bed, latency to sleep, awakenings and time awake, time they get out of bed, and total sleep time. Any daytime naps?

Is there a regular routine? Was there a change in schedule, weekday and weekend pattern, history of shift work?

Circadian rhythm disorders such as delayed sleep phase disorder can exacerbate insomnia. Patients may also attempt to go to bed earlier or later than usual, exacerbating the difficulty in falling asleep.

Does their schedule allow adequate opportunity for sleep?

d. Cognitions and psychiatric conditions

Worries about sleep extending into anxiety about other things, panic attacks, low mood, anhedonia, suicidal thoughts, trauma symptoms.

Screen for depression, anxiety and other psychiatric disorders like post-traumatic stress disorder, which would need to be concurrently managed.

e. History of sleep behaviours, including from bed partners

Loud snoring, apnoea, snort arousals, repetitive movements (e.g., twitching of toes or moving of legs), acting out of dreams or sleep-walking.

Sleep studies are not routinely done for insomnia, but may be needed to rule out other sleep disorders. Sleep state misperception can occur when patients perceive that they are awake, but are observed to be asleep.

f. Expectations and past treatment

What are they most worried about, and how does it affect them?

What have they done/tried, and did it work?

Having an idea of their expectations of sleep is important to understand which interventions may benefit them. Some associate the recall of dreams with poor sleep, and expect medications to ‘knock them out’.

g. Sleep hygiene & environment

Practices intended to improve sleep (e.g., staying in bed late, going to bed early, the use of alcohol and sleep aids).

Practices intended to counter fatigue (e.g., more caffeine/stimulants, reduced physical activity, napping).

Habits including clock watching and not winding down before bed.

Exploring the challenges in adhering to sleep hygiene can be helpful to tailor interventions. Past difficulties complying with sleep hygiene should be explored.

Is there revenge bedtime procrastination – trying to get more leisure time before bed, and excessive use of devices?

h. Other sleep disorders and medical conditions

Restlessness before bed (needing to walk/move, worse towards evening), nocturia, pain, breathlessness, headaches.

Any changes in medications, or existing chronic medical conditions? Are they going through menopause?

Insomnia may be precipitated or perpetuated by other physical issues which can disrupt sleep, though they may also be a sign of other underlying causes (e.g., sleep apnoea).

Stimulating medications can prevent sleep, while sedating medications cause sleepiness in the day.


There are many commercial products now available to monitor sleep. The use of wearable devices to monitor sleep has been promising, though studies show there is often a risk of overestimating or underestimating total sleep time.


Through sophisticated algorithms, the devices try to identify sleep, stages of sleep and quality. This has to be interpreted with caution, and at times may worsen insomnia if there is excessive monitoring of sleep.

The reliability of the devices will also be affected by underlying health conditions or sleep disorders, which limit the specificity with sleep stages and reliability of measuring time asleep.2,6


A key advantage of these devices is the collection of data over multiple nights at low cost, which might mitigate some of the limitations of a sleep study.

Future applications

As the technology develops, it may present opportunities for sleep disorder screening and incorporating these tools into treatment plans.

The use of digital sleep diaries, sometimes combined with wearable devices, also has great potential, though further evidence is needed to incorporate it into routine clinical practice.6


Sleep studies (e.g., polysomnography) are not usually done for insomnia, but may be performed if there are other sleep disorders to consider, such as sleep apnoea or periodic limb movement disorder.

A home sleep study may be used in cases with a high index of suspicion for underlying obstructive sleep apnoea (OSA).

An actigraphy may be used for suspected circadian rhythm disorders, or where the sleep log or history is not reliable.3-4


Treatment has to include the management of any comorbidities contributing to insomnia, in addition to the insomnia itself. Treatment options should take into account the features identified in history, suspected differential diagnoses, past treatments received and concerns with potential side effects.


Sleep hygiene education can be helpful for mild insomnia, but is rarely sufficient for more severe insomnia, which requires more directive behavioural interventions.

A sleep hygiene handout can be provided to patients, available from the SingHealth Duke-NUS Sleep Centre website here.


Cognitive behavioural therapy for insomnia (CBT-I) is the first-line recommendation for insomnia, even in the presence of other medical conditions.

It is a structured therapy with a psychologist, specifically designed for insomnia, that usually comprises about four to seven sessions for most patients.


However, access to CBT-I remains the biggest barrier worldwide. Some psychologists provide teleconsultations remotely which may help with accessibility, and some studies have found these modalities to be of equal efficacy to in-person sessions.5

Mobile applications

There are mobile applications that aim to deliver CBT-I, which increases accessibility and may overcome some of its usual challenges. Some of them are commercially produced, and some are free from research institutions and readily available.

There is evidence for its use to complement existing treatment, and it may also help with psychoeducation on sleep hygiene. A digital CBT-I application with promising evidence is in use in some healthcare settings in the United States and United Kingdom at a cost per user, but not currently available in Singapore.

There is a free application, produced by the U.S. Veterans Affairs’ National Center for PTSD, which incorporates CBT-I and is easily accessible. It includes interactive elements, tools and a sleep diary.2-3


Medications may be used for relief of symptoms, and should be considered in the context of the patient and illness characteristics.

As many medications used are sedating, there is an increased risk of falls, and the potential for impairment in functioning including risk of accidents from operating motor vehicles.

There is very limited evidence for the long-term use of medications. The risk-benefit of treatment and expectations should be discussed before starting on them. There may also be an additional role of using medications to complement ongoing CBT-I.5

a. Prolonged-release melatonin

Prolonged-release melatonin (Circadin) is a prescription-only medication that has been approved for insomnia in patients above the age of 55. It may be additionally useful in patients with circadian rhythm disorders, combined with behavioural changes and light therapy.

A melatonin receptor agonist (ramelteon) has been approved by the FDA for insomnia but is not available locally.6,8

b. GABAergic sedative hypnotic drugs or Z-drugs

GABAergic sedative hypnotic drugs, including benzodiazepines (e.g., clonazepam, lorazepam, alprazolam, diazepam) and benzodiazepine receptor agonists, or Z-drugs (e.g., zolpidem, zopiclone) can be effective in inducing sleep.

They can be prescribed for short-term use, especially in acute insomnia. However, prolonged use or abuse can lead to tolerance and dependence-forming habits, especially in those with chronic insomnia, and they should be stopped within four weeks.

There is an increased risk of falls in the elderly, and it can interfere with memory consolidation during sleep. In patients with suspected OSA, benzodiazepines should not be used as they can worsen sleep apnoea. Z-drugs may also cause parasomnias.2-5

c. Dual orexin receptor antagonists (DORA)

Dual orexin receptor antagonists (DORA) (e.g., lemborexant, suvorexant) are a new class of medications that works by inhibiting the orexinalerting system, which is affected in narcolepsy.

It can promote sleep when there is hyperarousal, hyperactivation or conditioned wakefulness, and appears to have a favourable side effect profile compared to some hypnotics. Side effects include sedation, abnormal dreams, headaches and dizziness.

Lemborexant has been recently approved for use in insomnia by the Health Sciences Authority (HSA) and is available locally.4

d. Antihistamines

Antihistamines (e.g., chlorpheniramine, hydroxyzine) are often used for insomnia, though there is very limited data supporting its use.

They are more accessible, though common complaints include oversedation continuing into the next day. They can also have significant anticholinergic side effects.2

e. Antidepressants

Antidepressants may be used off-label especially if there are comorbid mood or anxiety symptoms. More frequently used antidepressants include trazodone, mirtazapine, and tricyclic antidepressants like doxepin and amitriptyline which can be helpful.

In the elderly, caution is recommended due to the anticholinergic side effects. Doxepin 3 mg or 6 mg was approved for insomnia by the FDA, though locally those doses are not available.2,8

f. Anticonvulsants

Anticonvulsants (e.g., pregabalin, gabapentin) can be helpful especially in patients with pain, restless legs syndrome, generalised anxiety disorder and epilepsy.

g. Antipsychotics

Antipsychotics (e.g., quetiapine, olanzapine) are also used, but caution is required especially with their metabolic side effects.2


Primary care practitioners play a key role in screening and identifying patients suffering from insomnia and other sleep disorders, and treating them.

This includes:

  • Careful assessment for other comorbidities that may also require treatment
  • Being aware of both the role and limitations of medications in chronic insomnia
  • Managing the patient’s expectations with regard to medications, sleep and perceived sleep quality
  • Recommending behavioural changes before or together with the use of medications

Once patients are stabilised, they may also need ongoing monitoring and reassurance, as well as a plan should the insomnia relapse.


If comorbidity is suspected, or if patients do not respond to treatment, referral to a sleep specialist may be warranted. Psychiatrists at sleep centres see patients referred for insomnia, as well as patients with comorbid psychiatric disorders and sleep disorders.

At the SingHealth Duke-NUS Sleep Centre, there is a multidisciplinary team to evaluate the full range of sleep disorders. A comprehensive assessment is done, and if required, further investigations including a home sleep study or polysomnography can be performed.

At the Centre’s clinical sites at Singapore General Hospital, Changi General Hospital and Sengkang General Hospital, there are psychiatrists and psychologists to assess and manage patients presenting with insomnia, and patients may also receive CBT-I.


Insomnia is common and has significant consequences for an individual’s health and quality of life. There is a high comorbidity with other diseases which needs to be treated concurrently.

The mainstay of treatment should be behavioural therapy, though a growing range of pharmacological options do exist. With medications, caution and additional considerations include long-term use, side effects and potential for abuse and dependence. 

It helps to manage the patient’s expectations and follow up longitudinally, as behavioural change takes time.


  1. Lee YY, Lau JH, Vaingankar JA, et al. Sleep quality of Singapore residents: findings from the 2016 Singapore mental health study. Sleep Med X. 2022;4:100043. Published 2022 Jan 28. doi:10.1016/j.sleepx.2022.100043

  2. Krystal AD, Prather AA, Ashbrook LH. The assessment and management of insomnia: an update. World Psychiatry. 2019;18(3):337-352. doi:10.1002/wps.20674

  3. Paul S, Vidusha K, Thilagar S, Lakshmanan DK, Ravichandran G, Arunachalam A. Advancement in the contemporary clinical diagnosis and treatment strategies of insomnia disorder. Sleep Med. 2022;91:124-140. doi:10.1016/j.sleep.2022.02.018

  4. Rosenberg RP, Benca R, Doghramji P, Roth T. A 2023 Update on Managing Insomnia in Primary Care: Insights From an Expert Consensus Group. PrimCare Companion CNS Disord. 2023;25(1):22nr03385. Published 2023 Jan 24. doi:10.4088/PCC.22nr03385

  5. Perlis ML, Posner D, Riemann D, Bastien CH, Teel J, Thase M. Insomnia. Lancet. 2022;400(10357):1047-1060. doi:10.1016/S0140-6736(22)00879-0

  6. Guillodo E, Lemey C, Simonnet M, et al. Clinical Applications of Mobile Health Wearable-Based Sleep Monitoring: Systematic Review. JMIR Mhealth Uhealth. 2020;8(4):e10733. Published 2020 Apr 1. doi:10.2196/10733

  7. Erten Uyumaz B, Feijs L, Hu J. A Review of Digital Cognitive Behavioral Therapy for Insomnia (CBT-I Apps): Are They Designed for Engagement?. Int J Environ Res Public Health. 2021;18(6):2929. Published 2021 Mar 12. doi:10.3390/ijerph18062929

  8. Insomnia in the Elderly: Evaluation and Management. The Singapore Family Physician. 2021;47(1). doi:https://doi.org/10.33591/sfp.47.2.u3

Dr Leonard Eng is a Consultant with the SingHealth Duke-NUS Sleep Centre, and the Department of Psychiatry at Singapore General Hospital. He has a sub-specialty interest in sleep disorders and neurostimulation therapies for psychiatric disorders.

GPs can call the SingHealth Duke-NUS Sleep Centre for appointments at the following hotlines or click here to visit the website:

Singapore General Hospital: 6326 6060
Changi General Hospital: 6788 3003
Sengkang General Hospital: 6930 6000
KK Women's and Children's Hospital: 6692 2984
National Dental Centre Singapore: 6324 8798
National Neuroscience Institute: 6330 6363