Priority Topic: Insomnia

Key Feature 1: In patients presenting with sleep complaints, take a careful history to:

1. Distinguish insomnia from other sleep-related complaints that require more specific treatment (ex: sleep apnea or other sleep disorders, including periodic limb movements, restless legs syndrome, sleepwalking, or sleep talking).
2. Assess the contribution of drugs (prescription, over-the-counter, recreational), caffeine, and alcohol.
3. Make a specific psychiatric diagnosis if one is present. 

Skill: Clinical Reasoning, Selectivity
Phase: History, Diagnosis

Key Feature 2: When assessing patients with sleep complaints, obtain a collateral history from the bed partner, if possible. 
Skill: Clinical Reasoning
Phase: History

Later this week I'll be leading a teaching session with my resident peers on insomnia, so I need to do my due diligence and actually know a little bit about it beforehand. This is changing gears from my string of posts regarding pediatric issues lately, as this is not as common of a pediatric as adult complaint. 

Like with all presentations, for any complaint of sleep disturbance for whatever reason, I need to have a list of possible differential diagnoses. The DDx for sleep-wake disorders per the LMCC, which I find to be very logical, is broken down as follows:

1. External factors contributing to sleep disruption (ex: poor sleep environment)
2. Comorbid conditions (ex: dyspnea, substance abuse, neurologic disorders, psychiatric disorders) 
3. Intrinsic sleep disorders (ex: sleep-disordered breathing, circadian rhythm disorders, insomnia)

I like this differential because it provides a general framework, rather than listing off a series of specific causes, because there are SO MANY specific causes that may lead to sleep disturbance. Notice one of the skills for this Key Feature (#1) is "Selectivity." The clinician really needs to employ selective questioning as the patient interview unfolds to get at what truly is the disturbance and what could be causing it. That being said, general things to inquire about include

• What is the actual problem? (Ex: Falling asleep, staying asleep, waking up feeling unrefreshed, excessive daytime sleepiness) 
• Patient-centered history to get at what extrinsic, intrinsic, and comorbid factors may be causing or contributing to the sleep-wake disturbance (Ex: Associated symptoms/signs, diagnosed medical conditions, medications, substances)
• Obtain collateral information from a sleep partner to evaluate the patient's behaviour during sleep, such as if they snore or move a lot. 
• Consider information that may be provided by a sleep tracking device

It is also important to do a physical exam, as indicated, to look for such findings as overweight/obesity and elevated blood pressure (both associated with obstructive sleep apnea), signs of psychiatric distress such as depression or anxiety (which can be chicken or egg in relation to the sleep disturbance), and other signs of physical illness as indicated by the history.

Based on clinical assessment, if a medical (including psychiatric) disease is suspected, it is important to investigate, diagnose, and treat this as indicated. Like with any psychiatric illness, insomnia cannot be diagnosed until medical illness, medication effects or substance use, or other psychiatric illness is ruled out. If this is the case, the patient may meet the DSM-5 diagnosis of Insomnia Disorder:

Diagnostic Criteria
A. A predominant complaint of dissatisfaction with sleep quantity or quality, associated with one (or more) of the following symptoms:

1. Difficulty initiating sleep. (In children, this may manifest as difficulty initiating sleep without caregiver intervention.)
2. Difficulty maintaining sleep, characterised by frequent awakenings or problems in returning to sleep after awakenings. (In children, this may manifest as difficulty returning to sleep without caregiver intervention.)
3. Early-morning awakening with inability to return to sleep

B. The sleep disturbance causes clinically significant distress or impairment in social, occupational, educational, academic, behavioural, or other important areas of functioning.
C. The sleep difficulty occurs at least 3 nights per week.
D. The sleep difficulty is present for at least 3 months.
E. The sleep difficulty occurs despite adequate opportunity for sleep.
F. The insomnia is not better explained by and does not occur exclusively during the course of another sleep-wake disorder (ex: narcolepsy,  a breathing-related sleep disorder, a circadian rhythm sleep-wake disorder, a parasomnia).
G. The insomnia is not attributable to the physiological effects of a substance (ex: a drug of abuse, a medication).
H. Coexisting mental disorders and medical conditions do not adequately explain the predominant complaint of insomnia.

Specify if:

• With non-sleep disorder mental comorbidity, including substance use disorders
• With other medical comorbidity
• With other sleep disorder

Coding note: Code also the relevant associated mental disorder, medical condition, or other sleep disorder immediately after the code for insomnia disorder in order to indicate the association.

Specify if: 

• Episodic: Symptoms last at least 1 month but less than 3 months.
• Persistent: Symptoms last 3 months or longer
• Recurrent: Two (or more) episodes within the space of 1 year.

Note: Acute and short-term insomnia (i.e., symptoms lasting less than 3 months but otherwise meeting criteria with regard to frequency, intensity, distress, and/or impairment) should be coded as an other specified insomnia disorder.

An overview of the other DSM-5 sleep-wake disorder conditions: 

• Insomnia Disorder
• Hypersomnolence Disorder
• Narcolepsy
• Obstructive Sleep Apnea Hypopnea
• Central Sleep Apnea
• Sleep-Related Hypoventilation
• Circadian Rhythm Sleep-Wake Disorders
  • Delayed Sleep Phase Type (aka the night owl)
  • Advanced Sleep Phase Type (aka the morning type)
  • Irregular Sleep-Wake Type
  • Non-24-Hour Sleep-Wake Type
  • Shift Work Type
• Non-Rapid Eye Movement Sleep Arousal Disorders (manifested by sleepwalking or sleep terrors)
• Nightmare Disorder
• Rapid Eye Movement Sleep Behaviour Disorder
• Restless Legs Syndrome
• Substance/Medication-Induced Sleep Disorder
• Other Specific Insomnia Disorder
• Unspecified Insomnia Disorder
• Other Specified Hypersomnolence Disorder
• Unspecified Hypersomnolence Disorder
• Other Specified Sleep-Wake Disorder
• Unsepecified Sleep-Wake Disorder

That's just the DDx for a primary sleep-wake disorder. Now you may better appreciate my appreciation for the simplified DDx as listed by the LMCC approach to sleep-wake disturbance! At least this is a great starting point to frame one's clinical approach.