Risk factors for insomnia and potential complications

1. Risk factors

Due to the nature of insomnia triggers, anyone can become susceptible to developing this condition at any point in their lives, with or without certain risk factors. That said, certain risk factors, like behaviours, symptoms or underlying medical or mental (physical) conditions, can make a person more prone to episodes of insomnia.

Demographic risk factors:

Advanced age

Seniors over the age of 60 – 65 tend to start sleeping less than younger adults due to shifts in circadian rhythms, possibly due to a partial decline in the overall functionality of sleep/wake systems. ⁽¹⁰⁾ Seniors thus typically experience lighter sleep than younger adults, and increased sleep fragmentation. It is more typical for older adults to have difficulties with maintaining a sleep state than initiating sleep (younger adults prone to insomnia typically experience challenges with falling asleep).

Medical conditions, medication use and general physical changes as part of the aging process may also contribute to increasing risk for developing insomnia during the later years.

Gender

Females tend to be more susceptible to bouts of insomnia ⁽¹¹⁾, largely due to the unique hormonal shifts and patterns that are experienced throughout a woman’s life from puberty onwards. ⁽¹²⁾ Active hormonal shifts which commonly disrupt sleep include changes experienced during PMS (premenstrual syndrome), menopause (including the transitional period and after menopause), pregnancy, and the postpartum period.

Lifestyle behaviours

Engaging in habitual or maladaptive behaviours and activities either during the day or night before bedtime can influence the quality of sleep which can be achieved. Such behaviours or activities can place a person at higher risk of developing poor sleep habits, or experiencing disrupted sleep or insomnia, and can include:

• Use of tobacco / nicotine products (i.e. smoking)
• Consumption of beverages with disruptive properties, such as alcohol and caffeine
• Exercise activity in the evenings (particularly close to bedtime)
• Erratic morning and night-time routines
• Night shift work
• Engaging in mentally stimulating activities just before bed time, such as watching television, reading or working
• Long-range air travel (resulting in jet lag – crossing time zones in a short space of time disrupts a person’s biological rhythms)
• Sedentary habits (chronic inactivity)

Poor sleep environment

Where possible, distractions within the sleep environment should be removed or minimised in order to lower the risk of sleep disturbances and problems with insomnia.

Factors which contribute to a poor sleep environment and thereby, insomnia include:

• A bedroom that is either too hot or cold
• A sleeping environment that is exposed to noise
• A room that is too brightly lit
• An uncomfortable bed (mattress)
• A bed partner’s habits (i.e. a sleeping partner who moves around a lot or snores)
• Other individuals in the household with disruptive behaviours (as these people can influence other’s sleep capability or quality)

Chronic medical conditions

A variety of medical disorders and conditions, including chronic inflammatory or pain related illnesses, can cause sleep disturbance, influence sleep quality and increase a person’s risk of developing insomnia. Persistent insomnia (i.e. lasting longer than at least a month) can oftentimes be connected to a chronic condition, which may also involve the taking of appropriate medication. Such conditions include:

• Arthritis ⁽¹³⁾ 
• Diabetes (associated with diabetic neuropathy) ⁽¹⁴⁾ 
• Gastrointestinal reflux disease (GERD)
• Restless legs syndrome
• Fibromyalgia
• Alzheimer’s disease
• Dementia
• Parkinson’s disease
• Cancer (often a side-effect associated with treatment, involving pain, hospitalisation and stress)
• Heart disease (or cardiopulmonary disease) ⁽¹⁵⁾ 
• Hypertension / high blood pressure (systolic and diastolic blood pressure increases)
• Lung disease / pulmonary disease (nocturnal bronchoconstriction and breathing troubles, as well as secretions which tend to pool in the airways)
• Kidney disease or chronic renal failure
• Obstructive sleep apnoea
• Periodic limb movements of sleep (PLMS)
• Musculoskeletal conditions, such as carpal tunnel syndrome or tendonitis (associated with pain)
• Endocrine disorders, such as thyroid problems (overactive thyroid / hyperthyroidism) and menopause
• Dermatologic disorders (associated with itching)

Chronic health problems aggravated by heavy smoking habits and alcohol or drug use can also increase the risk of developing insomnia.

Psychological / psychiatric influences

Psychological factors can have an influence on both short-term and long-term sleep disruptions. Some triggers which contribute to increasing risk include:

• Stress vulnerability and hyperarousal susceptibility
• Mood disorders such as anxiety and anxiety disorders (including panic disorder), depression, bipolar disorder and post-traumatic stress disorder (PTSD) – chronic insomnia and various psychiatric conditions may coexist but should be treated independently. Insomnia can be treated as both a symptom of a coexisting disorder and as an independent condition. As a symptom, insomnia can oftentimes develop before other more noticeable clinical signs of a psychiatric disorder. It can also develop around the same time. Hence, diagnosis of either condition can overlap. Resolving one condition will not necessarily automatically correct the other. Insomnia can persist even if the other disorder is under better control.
• Personal trauma or life pressures (e.g. work-related problems or unemployment, financial constraints - often influenced by lower incomes, problems within the family or a marriage, exposure to a traumatic event, the development of a serious illness or the loss of a loved one).

Medication use

The risk of insomnia as a side-effect is often associated with the following types of medications:

• Over-the-counter decongestants, as well as medications for the treatment of the common cold and coughs
• Steroid medications
• Appetite suppressants
• Stimulants like caffeine, methylphenidate (Ritalin) used to treat attention deficit disorder (ADD), attention deficit hyperactivity disorder (ADHD) and narcolepsy and Modafinil (Provigil) used to treat disorders causing daytime sleepiness, narcolepsy, obstructive sleep apnoea and shift-work sleep disorder.
• Hypertension (high blood pressure) medications (beta blockers)
• Selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) (used in the treatment of depression)
• Norepinephrine and dopamine reuptake inhibitors
• Monoamine oxidase inhibitor antidepressants
• Tricyclic antidepressants
• Levodopa (a medication treatment for Parkinson’s disease)
• Theophylline and bronchodilators (used in the treatment of asthma)
• Phenytoin (medication treatment for seizure disorders)
• Opioids (while these generally have a sedative effect, long term use can lead to changes in sleep architecture causing fragmented sleep, night time awakenings and issues with breathing that contribute to sleep disorders.
• Glucocorticoids (for the treatment of various inflammatory conditions)

Discontinuation of either prescription or over-the-counter medications (including sleeping pills) can place a person at risk of experiencing ‘rebound insomnia’ (this is likely to be a temporary disruption).

2. Potential complications 

If comorbidity is not a factor (i.e. insomnia does not co-exist with another medical or mental health condition), it is usually possible to achieve recovery within a few weeks without repercussions or complications. 

The most common complaint regarding insomnia is a constant feeling of being tired. The effect of this also contributes to regular issues with being able to concentrate and focus adequately enough for normal daily function.

If left untreated, insomnia can result in the following:

• Increased difficulties with concentration, memory function, coping ability (particularly with minor irritations) and problems with maintaining positive personal and social relationships.
• Increasingly poor quality of life (most often associated with anxiety or depressive disorders).

Those who experience sleep disruptions which are brought on by intense trauma (such as in those experienced by PTSD sufferers), or that develop due to dependence on prescription medications to induce sleep (like sleeping pills), often experience difficulties in overcoming insomnia, even if under treatment.

It is well-known that insomnia is closely associated with anxiety and depressive disorders, not only as a risk factor or trigger, but also as a potential complication - particularly in the case of chronic insomnia. The risk of developing these types of mood disorders is often highest during periods of insomnia. It is not difficult to see why. Chronic sleeplessness can result in a loss of pleasure in life and cause anxiety, both of which may lead to depression.

Potential problems which can arise if insomnia triggers severe anxiety or depression include complications associated with alcohol or drug dependence (addictions) or even the risk of suicide.

Individuals affected by chronic insomnia may also develop medical conditions due to physical strain factors, such as hypertension (high blood pressure).

It has been established that treating sleep disruptions (insomnia) as a secondary condition to a coexisting medical or mental health disorder may not necessarily resolve insomnia symptoms. Insomnia may persist even with effective treatment for the other diagnosed condition. This can then contribute to an increased risk of a relapse in the other medical or mental health condition.

References:

^{10. US National Library of Medicine - National Institutes of Health. 24 April 2007. Sleep and aging: 1. Sleep disorders commonly found in older people: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1852874/ [Accessed 04.08.2018]}

^{11. National Sleep Foundation. Women and Sleep: https://sleepfoundation.org/sleep-topics/women-and-sleep  [Accessed 04.08.2018]}

^{12. US National Library of Medicine - National Institutes of Health. 2013. Sleep and Women's Health: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4327930/ [Accessed 04.08.2018]}

^{13. US National Library of Medicine - National Institutes of Health. March 2015. Sleep Disturbance in Osteoarthritis: Linkages with Pain, Disability and Depressive Symptoms: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4342277/ [Accessed 04.08.2018]}

^{14. US National Library of Medicine - National Institutes of Health. 25 June 2015. Effect of diabetes mellitus on sleep quality: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4478581/ [Accessed 04.08.2018]}

^{15. Oxford Academic. February 2007. Comorbidity of Chronic Insomnia With Medical Problems: https://academic.oup.com/sleep/article/30/2/213/2709239 [Accessed 04.08.2018]}