Lecture 12: Insomnia Flashcards
How is insomnia perceived?
Not as a symptom of another somatic or mental disorder but makes up an independent disorder, usually occurring as a comorbid condition than on its own. Seen as made up of different phenotypes, which is linked to different personality features than sleep features
What is important to consider when diagnosing insomnia disorder?
- sleep diaries are important for insomnia assessment focus on the experience of sleep or can use insomnia questionnaires
- different paradigms used to look at specific aspects: attentional bias paradigm, failing overnight amelioration
- based on subjective processes but polysomnography (PSG) could be useful in looking at limb movements
- major clinical challenge is the difference between subjective and objective data
Why is there a discrepancy btw subjective and objective measurements?
There is conflicting results: 25 min difference between insomnia and good sleepers while subjective estimates demonstrated a 2 hour difference. There could be mismeasurement which is an inappropriate use of the PSG features.
What is the epidemiology of insomnia and how is it a risk factor for other disorders?
- insomnia affects females more than males, prevalence increasing with age
- around 10% of adult population suffers from chronic insomnia
- increased risks for: cardiovascular diseases, obesity, depression, anxiety and suicide
- has immensely high risks and costs
What is the 3 p model of insomnia?
Predisposing factors: epigenetics and early life stress contribute to individual differences at brain function and personality
Precipitating factors can be easily identified, involving life events that can facilitate the onset of acute episodes of insomnia. Can be: family, health and work- school living with negative emotional valence
Perpetuating: typical one is hyperarousal like overactivity of arousal-promoting systems which can include physiological, cognitive and emotional components. Linked to greater autonomic activity and overactivity of HPA-axis, importance of REM to discard hyperarousal
What is the flip-flop switch model of sleep regulation?
Suggests a switch mechanism between sleep and wake promoting centres of neuron cell groups. Wakefulness: cell populations in hypothalamus, basal forebrain and brain stem, thalamus and cortical structures. Main sleep-inducing centres are in the ventrolateral-preoptic nucleus (VLPO) which is active in sleep and inhibits wake-promoting centres with GABA. Seen as an imbalance between sleep-inducing states and wake-inducing mechanisms. Insomnia can result from hyperactivity from arousal system or hypoactivity of sleep system
What is the two process model of sleep regulation?
Sleep-wake behaviour determined by circadian mechanisms and controlling process S which represents sleep drive. Being out of synchrony with internal body clock or less sleep drive can result in sleep complaints. This principle used for CBT-I sleep restriction.
What is the role of emotion in predisposing insomnia?
For evolution purposes, in stressful conditions it would be disadvantageous to sleep. Difficulties with emotion regulation is linked to insomnia like neuroticism, perfectionism, sensitivity to anxiety. Genes predisposing insomnia also have links with emotion
What is the role of restless REM sleep?
- insomnia interferes with overnight adaptation in limbic circuits, so difficulties with dissolving distress can perpetuate hyperarousal
- increased level of noradrenaline could interfere with synaptic plasticity processes
- linked with emotional factors-> more prone to develop anxiety and depressive disorders
What is the role of inadequate behaviours for perpetuating factors?
Can include prolonged bedtimes, irregular sleep-wake schedules, napping during the day, using alcohol to combat insomnia. Try to compensate for lost sleep but maintained and worsened by decreased sleep drive
What is the role of cognitive perpetuating factors?
Can involve cognitions like unrealistic beliefs about sleep requirements and excessive worry not meeting them. The attentional system of those with insomnia is more sensitive to sleep-related information
What is CBT-I?
- has multiple components like sleep restriction, stimulus control, reappraisal, cognitive control, paradoxical intention, sleep hygiene education
- single-component therapies being looked at like sleep restriction therapy
- CBT protocol still found to be effective when they vary
- CBTx seen as therapeutic formulary so not everyone needs the same content or same order
- digital CBT found to be effective in further clinical and functional outcomes like reducing anxiety and depression, also found to be effective in practice
How is CBT being enforced as the first choice of treatment?
- linked to under-provision of CBT rather than over-prescribing drugs
- large evidence base of digital CBT-I and the development of the stepped care model of insomnia
What is the stepped care model?
Pyramid of different levels, with the bottom for least specialized help for those with less severe, more generic complaints to highly specialized help for those with more severe, complex and rare problems at the top. So treatment is tailored to the needs of the patient. Digital CBT-I could be good for entry level, or using self-help books. Followed by insomnia services with some in-person support (could be group therapy). As you go up, more need for specialist expertise and more specialize facilities. Difficult to identify the appropriate level of care and making sure people can step up to more advanced care.
What is the future for sleep research?
- using the same insomnia criteria
- identifying different phenotypes
- use of standard methodology and paradigms across labs
- developing hyperarousal test like stress/challenge paradigm
- CBT-I should be the first-line treatment for insomnia
- better understanding of psycho-neurobiological mechanisms to evaluate treatment like 1 night of sleep restriction to stabilize sleep restriction and acknowledging low full remission rates, and wearing off of the initial benefits of CBT-I
