What Is Insomnia?
Insomnia disorder is defined as difficulty initiating sleep, maintaining sleep, or waking too early, occurring at least three nights per week for at least three months and causing clinically significant daytime impairment. This is distinct from occasional bad sleep, which almost everyone experiences.
Chronic insomnia is common. A large 2024 Canadian population study estimated the prevalence of insomnia disorder at 16.3 percent, with higher rates in women, Indigenous populations, and people with poorer physical or mental health. Roughly 40 percent of people with chronic insomnia continue to have symptoms five years later without effective treatment.
Insomnia is not a symptom to endure. It's a treatable disorder with a well-defined mechanism and an evidence-based first-line therapy that most Canadians never get offered.
How Insomnia Works: The Hyperarousal Model
The dominant neurobiological model of chronic insomnia is hyperarousal. In insomnia disorder, the arousal systems that should quiet down at night, cortical, autonomic, and HPA-axis, stay too active. Quantitative EEG studies show elevated high-frequency activity (beta) at sleep onset and during sleep in insomnia patients compared with controls. Overnight cortisol is elevated. Heart rate variability shows persistent sympathetic dominance.
The clinical experience of this is familiar: the body is tired, the mind won't stop. It's not a will problem. It's the arousal system being on when the sleep system is supposed to take over.
The 3P Model (Spielman)
A widely-used clinical framework separates three types of factors:
- Predisposing factors: baseline traits that raise insomnia risk, family history, tendency toward hyperarousal, perfectionism, being female, older age.
- Precipitating factors: the event that started this episode, stress, life change, illness, grief, a new medication, having a baby.
- Perpetuating factors: what keeps it going after the precipitant has passed, spending more time in bed to "catch up," anxious monitoring of sleep, unhelpful beliefs ("I need 8 hours or I can't function"), daytime napping, checking the clock, associating the bed with wakefulness rather than sleep.
The precipitant may be long gone, but the perpetuating factors are what turn acute insomnia into chronic insomnia. CBT-I targets those perpetuating factors directly.
Why Sleep Medication Is Not the Answer
Sleep medication has a role in short-term or crisis use, but it's not the treatment for chronic insomnia disorder, and the guidelines are clear on this point. The 2021 and 2024 American Academy of Sleep Medicine guidelines strongly recommend CBT-I as the first-line treatment for chronic insomnia in adults, with medication as a secondary option when CBT-I is not available, not effective, or not preferred.
Limitations of medication for chronic insomnia:
- Effect sizes on total sleep time and sleep quality are modest.
- Tolerance develops; escalating doses are common.
- Dependence and withdrawal (particularly with benzodiazepines and Z-drugs like zopiclone) are common and clinically significant.
- Rebound insomnia on discontinuation is well-documented.
- Long-term use is associated with cognitive impairment, falls in older adults, and other safety concerns.
- Medication does not change the underlying arousal or the perpetuating factors, so when it stops, insomnia usually returns.
None of this means that anyone currently on sleep medication has done something wrong. It means the treatment landscape has changed, and CBT-I should now be the offered starting point.
How Therapy Helps: CBT-I
CBT-I is a structured, short-term treatment typically delivered over 4 to 8 sessions. It has the strongest evidence base of any insomnia treatment and produces durable gains that persist after therapy ends.
Core components:
- Sleep restriction therapy: temporarily narrowing the time you spend in bed to match the sleep you're actually getting, which increases sleep drive and consolidates sleep. Counterintuitive but powerful.
- Stimulus control: rebuilding the automatic association between bed and sleep by getting out of bed when you can't sleep and reserving the bed for sleep and intimacy only.
- Cognitive restructuring: examining and updating the anxious beliefs about sleep that keep the arousal system activated, "if I don't sleep I'll fall apart tomorrow," "I need exactly 8 hours."
- Sleep hygiene education: light exposure, caffeine and alcohol timing, room environment. Necessary but not sufficient on its own.
- Relaxation and arousal-reduction techniques: to lower the physiological hyperarousal at bedtime.
CBT-I is not gentle in the first two weeks (sleep restriction usually means less sleep before it means more), but the trajectory is reliable. Most people begin to see improvement by session 3 or 4.
Brief Behavioural Treatment for Insomnia (BBT-I)
A shorter, more accessible variant (typically 4 sessions or fewer) focused on sleep restriction and stimulus control. Useful when time or access are barriers, with growing evidence in primary-care and specialty populations.
Digital CBT-I
Therapist-guided and self-guided digital CBT-I programs have solid evidence and can extend access. We can discuss whether in-person, virtual, or hybrid delivery makes the most sense for your situation.
Insomnia and Comorbidities
Insomnia rarely comes alone. It commonly co-occurs with:
- Depression and anxiety: bidirectional relationship, and treating insomnia often meaningfully improves both.
- Chronic pain: pain disrupts sleep, and poor sleep amplifies next-day pain.
- ADHD: adult ADHD has a strong sleep component (delayed sleep phase, arousal dysregulation).
- Post-concussion syndrome: sleep disruption is common after concussion and one of the highest-leverage things to treat.
- Menopause and perimenopause: hot flashes, hormonal shifts, and secondary hyperarousal.
- PTSD: insomnia and nightmares are core features of PTSD; CBT-I adapted for PTSD is effective.
Treating insomnia in the context of these conditions often unlocks improvement across the board.
Our Approach at Toronto Mental Health Clinic
We deliver CBT-I as it was designed, structured, protocol-based, adapted where necessary to the individual. Our clinician team includes practitioners with specific CBT-I training, and we are willing to work alongside your family doctor or sleep specialist if you're currently on sleep medication and want to taper. We do not recommend abrupt discontinuation.
We also treat insomnia in the context of what else is going on: chronic pain, ADHD, mood or anxiety difficulties, post-concussion recovery. The full picture matters.
Getting Support
If you've been managing chronic insomnia with medication, herbal aids, or willpower for months or years, and no one has offered you CBT-I, that is a treatment gap worth closing. A first conversation with one of our clinicians is a good place to start.
This page provides general educational information about insomnia and is not a substitute for individualized clinical assessment or medical advice. If you are on sleep medication, do not discontinue without medical guidance.