Insomnia – Condition or Symptom of Comorbidity

Insomnia Comorbidities

Insomnia is a symptom that arises from multiple environmental, medical, psychological and mental health disorders.¹ A high rate of comorbidities exists between chronic insomnia and medical and psychiatric disorders.² It is estimated that 10-15% of patients who have chronic insomnia are of primary origin.¹ Insomnia that is comorbid with psychiatric disorders, medical disorders, circadian rhythm disorders, or substances or medications accounts for nearly 85-90% of chronic insomnia.¹

Comorbid Psychiatric Conditions

Many patients with psychiatric disorders experience chronic insomnia.³ Individuals with insomnia are more than five times as likely to present anxiety or depression.² Insomnia frequently occurs in people with anxiety, mood, impulse-control and substance use disorders.² The table below reviews some key information on comorbid psychiatric conditions.

Insomnia is a risk factor for new onset psychiatric disorders, most notably depression, anxiety and substance use disorders.²

Common Comorbid Psychiatric Conditions with Insomnia^1-4
Mood Disorders	Examples: Major depressive disorder, bipolar mood disorder, dysthymia Ninety percent of patients with major depressive disorder report insomnia or daytime sleepiness Individuals with insomnia are four times more likely to develop new major depression over the next 3.5 years than individuals without insomnia Resolving depression may also help to improve insomnia
Anxiety Disorders	Examples: Generalized anxiety disorder, panic disorder, posttraumatic stress disorder, obsessive compulsive disorder Most commonly associated with generalized anxiety disorder (GAD) and post-traumatic stress disorder (PTSD) Patients with insomnia are twice as likely to develop an anxiety disorder over the next 3.5 years than individuals without insomnia Many of these patients have problem initiating and maintaining sleep Treatment of GAD can improve insomnia, whereas the results with PTSD treatment is inconsistent
Schizophrenia	Sleep disorders are very common in this patient population Treatment of schizophrenia generally enhances sleep
Dementia	Examples: Alzheimer disease and other dementias Conditions are associated with multiple awakenings and daytime somnolence Dementia can also cause a variety of circadian rhythm abnormalities

Comorbid Physical Disorders

There are a number of medical conditions that are commonly associated with insomnia. The most common comorbid conditions involved chronic pain, gastrointestinal problems, breathing difficulties, heart disease, urinary problems and neurological disorders.⁴

The table below reviews some of the most common medical comorbidities with insomnia.

Common Medical Comorbid Conditions with Insomnia4–6^4-6
Chronic Pain	Insomnia may occur in the setting of chronic pain Approximately 25% of patients with suffer from clinical insomnia Insomnia is very common in patients with osteoarthritis, rheumatoid arthritis, headache and fibromyalgia There is a bi-directional relationship with pain and insomnia. Patients with insomnia, experience more severe pain, longer pain duration, greater levels of anxiety, depression and health anxiety, and worse impairment in physical and psychosocial functioning
Obstructive sleep apnea	Sleep disorders are common in people with obstructive sleep apnea syndrome The main symptoms of which are snoring, breathing pauses during sleep, choking, gasping, morning dry mouth, and headaches
Restless leg syndrome	Symptoms of restless legs syndrome include an irresistible urge to move the extremities, limb paresthesia, onset of symptoms during period of rest and in the evening or at bedtime, and relief of symptoms with movement
Gastroesophageal reflux disorder (GERD)	Epigastric pain or burning, laryngospasm, acid taste in mouth, sudden nocturnal awakenings
Respiratory conditions	COPD is commonly associated with insomnia This is primarily due to dyspnea
Other conditions	Benign prostatic hypertrophy Diabetes Parkinson's disease Huntington's chorea Progressive dystonia Tourette's syndrome Epilepsy

Medications can Commonly Worsen Insomnia

It is not only psychiatric and medical conditions associated with insomnia, but also the medications used to manage them. Several common medications such as antidepressants and opioids used for chronic pain are associated with worsening sleep disturbances.³ The table below reviews some of the most common medications associated with insomnia.

Common Medications Associated with Insomnia³
Category	Examples
Antidepressants	SSRIs - fluoxetine, paroxetine, sertraline, citalopram, escitalopram, fluvoxamine SNRIs - venlafaxine, duloxetine Monoamine oxidase inhibitors
Stimulants	Caffeine Methylphenidate Amphetamine derivatives Cocaine
Decongestants	Pseudoephedrine Phenylephrine
Cardiovascular	Β-blockers α-receptor agonists and antagonists diuretics Lipid lowering medications
Bronchodilators	Theophylline Short-acting beta agonists - Salbutamol Long-acting beta agonists – salmeterol, formoterol
Alcohol	Chronic and acute consumption

The ideal treatment for the management of insomnia would be to address the patient’s underlying insomnia.

References:

Reddy MS, Chakrabarty A. “Comorbid” Insomnia. Indian J Psychol Med. 2011;33(1):1-4. doi:10.4103/0253-7176.85388
Morin CM, Benca R. Chronic insomnia. The Lancet. 24;379(9821):1129-1141. doi:10.1016/S0140-6736(11)60750-2
Schutte-Rodin S, Broch L, Buysse D, Dorsey C, Sateia M. Clinical Guideline for the Evaluation and Management of Chronic Insomnia in Adults. J Clin Sleep Med. 2008;4(5):487-504.
Roth T. Comorbid insomnia: current directions and future challenges. Am J Manag Care. 2009;15 Suppl:S6-13.
Jank R, Gallee A, Boeckle M, Fiegl S, Pieh C. Chronic Pain and Sleep Disorders in Primary Care. Pain Res Treat. 2017;2017. doi:10.1155/2017/9081802
Tang NKY. Insomnia Co-Occurring with Chronic Pain: Clinical Features, Interaction, Assessments and Possible Interventions. Rev Pain. 2008;2(1):2-7. doi:10.1177/204946370800200102