Insomnia

Patients with insomnia have impaired daytime function due to difficulty initiating sleep, difficulty maintaining sleep, or waking up early in the morning without ability to return to sleep [7]. They complain of fatigue, loss of energy, depression and irritability during the day and disturbed sleep during the night. A detailed history may reveal the use of certain medication that may point towards an underlying disease. If the patient is suffering from a psychological condition, it may present with characteristic symptoms like delusions, hallucinations, confusion, anxiety, depression and personality changes. If the insomnia is associated with other diseases, presenting complains of insomnia will be accompanied with systemic signs and symptoms.

Physical examination may offer clues to underlying medical disorders predisposing to insomnia [8]. A detailed history is imperative in making the right diagnosis.

Laboratory tests

• Arterial blood gases
• Blood oximetry
• Routine blood tests like complete blood count (CBC), prothrombin time, thyroid function tests, liver function tests, kidney function tests to rule out underlying disease.

Imaging

• ECG
• Polysomnography
• Actigraphy
• Radiography and CT scan to exclude other diseases

Test results

The diagnosis of insomnia is a difficult one and is easily confused with sleep apnea. A detailed history and the use of a sleep diary or log book can aid in making the right diagnosis.

Medication

Since insomnia can precipitate, exacerbate, or prolong comorbid conditions, treatment of insomnia may improve comorbidities [9]. Treatment is based on chemotherapy that includes sedatives like benzodiazepines, and non-benzodiazepines receptor agonists like Zolpidem and Eszopiclone. Other drugs that can be used to treat or at least provide symptomatic relief include Melatonin, or Melatonin-receptor agonists like Ramelteon, Orexin receptor antagonist like Suvorexant, sedative anti-depressants like Doxepin, and antihistamines.

Non-pharmalogical treatment

It includes hypnotic treatment to induce and improve sleep and cognitive behavioural therapy (CBT). CBT is a good way of treating insomnia and is recommended along with pharmacological treatment.

Insomnia may disappear on its own if the predisposing factor is removed or treated. In cases where the predisposing factor(s) or underlying condition persists, insomnia is a progressive disease. It may begin with disturbed sleep and progress to severe depression, loss of memory and a reduced quality of life. People who are able to sleep for only 5 hours or less on long term basis have high mortality rates.

Insomnia has a diverse range of potential causes. First and foremost is stress. Stress could be due to personal, professional, social or financial conditions which would make the person anxious and depressed, causing insomnia. Some patients may be insomniacs due to a genetic predisposition. A missense mutation has been found in the gene encoding the GABAA beta 3 subunit in a patient with chronic insomnia [3].

Other causes include preexisting medical conditions like heart disease, gastrointestinal problems, urinary problems, persistent pain, hypertension or respiratory problems. Restless legs syndrome or periodic limb movement disorder may be causing insomnia and so can be mental disorders like PTSD, schizophrenia and bipolar disorder. Hormone shifts, like those occurring during premenstrual syndrome (PMS) or pregnancy, increased use of nicotine and caffeine, and some stimulant medications like amphetamines may cause insomnia.

Incidence

It is a very common medical complaint in primary care patients and the same is true for patients in palliative care, which is illustrated by studies that report the prevalence of insomnia is over 70 percent [4].

Age

Insomnia is very rare in children, unless it is accompanied with a medical condition that disturbs sleep. Acute insomnia can affect adolescents and old aged people alike but is generally a frequent complain of people in the prime of life. Chronic insomnia on the other hand is much more common in the elderly.

Sex

Insomnia is 40% more common in women than in men [5].

The DSM-5 criteria for insomnia include the following [6]:

Difficulty initiating and maintaining sleep, and difficulty going back to sleep after awakening early. The symptoms must be present at least 3 times a week for 3 months to be declared insomnia. The symptoms should also persist despite adequate opportunities to sleep and without any effects of drugs, narcotics or alcohol.

Types

Although insomnia can be classified into many subtypes, it can be divided into 3 broad categories:

• Acute insomnia

It lasts for less than a month and then goes away on its own. It is triggered by either environmental factors such as travelling, change in environment, change in routine, or stress and depression. It is also known as transient insomnia (symptoms lasting for less than a week) and adjustment insomnia.

• Primary insomnia

This condition fits the DSM-5 criteria for insomnia. It is characterized by inability to sleep during desired time or inability to maintain sleep for a longer time. The duration of sleep may be punctuated by periods of heightened awareness of the surroundings, heightened somatic tension and intrusive thoughts.

• Chronic insomnia

This condition lasts for more than 1 month and is mostly due to a medical condition such as heart disease, breathing problems, conditions causing nocturia, diseases associated with persistent pain like arthritis, hypertension or gastrointestinal problems. If chronic insomnia exists without an underlying medical condition, it is due to high stress.

Good sleep hygiene plays an important role in preventing insomnia. It includes setting up and maintaining a regular sleep schedule with regular sleep and wakening timings, avoiding caffeinated drinks and high sugar containing food a few hours before going to bed. A calm quiet environment and a healthy diet and lifestyle also go a long way in helping attain good sleep.

Insomnia was previously viewed as a sleep disturbance that was secondary to a medical condition, psychiatric illness, sleep disorder, or medication, and would improve with treatment of the underlying disorder [1]. But now, insomnia is recognized as an independent disorder [2]. It is a common complaint in outpatient care departments and is most frequently associated with stress.

Definition

Insomnia is defined as a condition of sleeplessness. There may be inability to fall asleep, maintain sleep or to go back to sleep after awakening early. 

Cause

Insomnia is primarily due to stress. Other causes include heart, gastrointestinal and urinary diseases, breathing problems, pain, mental conditions, disrupted sleep schedule or lifestyle, environmental change, drug side effects and genetic factors.

Signs and symptoms

Insomnia often coexists with other symptoms, such as pain, depression, and anxiety and the presence of one often exacerbates the other, contributing to a decrease in quality of life [10]. It presents with inability to fall asleep or maintain sleep for longer than a few hours at night, and irritability, tiredness and loss of energy during the day. 

Diagnosis

Insomnia is diagnosed by excluding other underlying diseases that may be causing sleep disturbances. A thorough physical examination and laboratory tests aid in that endeavour. A detailed history helps in making the right diagnosis.

Treatment

Treatment includes the use of prescribed drugs along with cognitive behavioural therapy. Lifestyle changes also help. 

1. National Institutes of Health. National Institutes of Health State of the Science Conference statement on Manifestations and Management of Chronic Insomnia in Adults, June 13-15, 2005. Sleep 2005; 28:1049.
2. Katz DA, McHorney CA. Clinical correlates of insomnia in patients with chronic illness. Arch Intern Med 1998; 158:1099.
3. Buhr A, Bianchi MT, Baur R, Courtet P, Pignay V, Boulenger JP, et al. Functional characterization of the new human GABA(A) receptor mutation beta3(R192H). Hum Genet. Aug 2002;111(2):154-60
4. Hugel H, Ellershaw JE, Cook L, et al. The prevalence, key causes and management of insomnia in palliative care patients. J Pain Symptom Manage 2004; 27:316.
5. "Several Sleep Disorders Reflect Gender Differences". Psychiatric News 42 (8): 40. 2007.
6. "Sleep Wake Disorders." Diagnostic and statistical manual of mental disorders: DSM-5.. 5th ed. Washington, D.C.: American Psychiatric Association, 2013
7. International Classification of Sleep Disorders, 3rd ed, American Academy of Sleep Medicine, Darien, IL 2014
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10. Glynn J, Gale S, Tank S. Causes of sleep disturbance in a specialist palliative care unit. BMJ Support Palliat Care 2014; 4 Suppl 1:A56.