Is CBT-I or ACT-I More Effective for Insomnia?

Both therapies produce clinically meaningful improvements, with comparable outcomes across multiple studies and systematic reviews [2][4]. CBT-I has the more extensive evidence base built over several decades and remains the recommended first-line treatment. ACT-I has a growing body of research and shows particular advantages for people with high sleep anxiety and poor daytime functioning. For many people, an integrated approach combining both therapies is more effective than either alone.

Can I Try ACT-I if CBT-I Did Not Work for Me?

Yes. If CBT-I improved some behaviours around sleep but anxiety and hypervigilance remained — or if the improvement did not hold over time — ACT-I addresses the psychological struggle response that CBT-I may not have fully resolved [4]. The two therapies work through different mechanisms, so ACT-I is not simply a fallback; it targets what CBT-I does not directly reach.

What Is the Paradox of Sleep Control?

The paradox of sleep control is that trying hard to sleep increases arousal, which makes sleep less likely [5]. The more vigilant and effortful your relationship to sleep becomes, the more your brain interprets bedtime as a threat. ACT-I works by helping you reduce that effortful struggle, which allows your nervous system to settle and your natural sleep ability to return.

What Is Cognitive Defusion and How Does It Help with Insomnia?

Cognitive defusion is an ACT-I technique for changing your relationship to intrusive thoughts without trying to eliminate them. Rather than treating the thought “I will be ruined tomorrow” as a fact that demands action, you learn to observe it: “I notice I am having the thought that I will be ruined tomorrow.” This creates psychological distance from the thought and reduces the arousal it generates, which is particularly valuable when catastrophic thoughts about sleep are contributing to your sleeplessness.

Is CBT-I or ACT-I Better for Insomnia During Perimenopause?

Both therapies are effective for insomnia triggered or worsened by perimenopause. Hormonal changes can disrupt sleep architecture directly, but they also trigger learned patterns of hyperarousal and anxiety around sleep that can persist even after hormonal symptoms improve [3]. An integrated CBT-I and ACT-I approach is often particularly well suited to this population, since perimenopause frequently intensifies sleep anxiety in ways that a rigid protocol alone can struggle to address.

CBT-I vs ACT-I for Insomnia: What's the Difference, and When Does Each Work Best?

What Is CBT-I?

Cognitive Behavioural Therapy for Insomnia (CBT-I) is the first-line, evidence-based treatment for chronic insomnia recommended by NICE (National Institute for Health and Care Excellence) and the NHS 1. It has the most extensive evidence base of any insomnia intervention, built over decades of randomised controlled trials.

CBT-I works by identifying and changing the specific thoughts and behaviours that maintain insomnia. It is not a generic application of CBT (cognitive behavioural therapy). It is a precise protocol developed specifically for sleep.

The core components of CBT-I include:

Sleep Restriction — temporarily compressing time in bed to rebuild sleep drive and reduce conditioned wakefulness (the learned association between lying in bed and being awake)
Stimulus Control — re-associating the bed and bedroom with sleep rather than with wakefulness and anxiety
Cognitive Restructuring — identifying and challenging unhelpful beliefs about sleep, such as “I need eight hours or I cannot function” or “If I do not sleep now, I have ruined tomorrow”
Sleep Hygiene — the behavioural conditions that support sleep, though this is typically the least impactful component for people with established chronic insomnia
Relaxation Techniques — used selectively to reduce physiological arousal (the state of heightened alertness that interferes with sleep onset)

Research consistently shows that around 70–80% of people with chronic insomnia see significant improvement through CBT-I, and the gains tend to be durable 2.

What Is ACT-I?

Acceptance and Commitment Therapy for Insomnia (ACT-I) is an adaptation of Acceptance and Commitment Therapy applied specifically to sleep. It approaches insomnia from a fundamentally different angle to CBT-I.

Where CBT-I says change the thoughts and behaviours that are making sleep worse, ACT-I says stop fighting sleep, reduce the struggle response, and allow your natural sleep ability to emerge from beneath the fear.

The core insight of ACT-I is the paradox of sleep control: the harder you try to sleep, the more your brain registers wakefulness as a threat, which increases arousal, which makes sleep less likely 5. Many people with chronic insomnia have become so vigilant about sleep — monitoring it, analysing it, trying to engineer it — that the effort itself has become a central part of what is maintaining the problem.

ACT-I works through:

Acceptance — reducing resistance to wakefulness and the discomfort of not sleeping, which paradoxically lowers the arousal that blocks sleep
Defusion (separating yourself from your thoughts) — learning to observe intrusive sleep-related thoughts without being controlled by them; for example, “I notice I am having the thought that I will never sleep properly again” rather than treating that thought as fact
Values-Based Engagement — reconnecting with daytime life and activity rather than organising everything around sleep recovery
Mindfulness (present-moment, non-judgemental awareness) — reducing the rumination and future-focused anxiety that maintain insomnia
Committed Action — choosing sleep-supportive behaviours not as rigid rules to follow but as expressions of what genuinely matters to you

ACT-I for insomnia has a growing and robust evidence base. Systematic reviews confirm it produces outcomes comparable to CBT-I, with particular advantages in reducing sleep-related anxiety and improving daytime functioning 4.

How CBT-I and ACT-I Compare

	CBT-I	ACT-I
Primary Mechanism	Change thoughts and behaviours	Reduce struggle; increase psychological flexibility
Approach to Unhelpful Thoughts	Challenge and reframe them	Observe them without engagement (defusion)
Approach to Wakefulness	Reduce it through sleep restriction and stimulus control	Accept it without struggling against it
Evidence Base	Extensive — decades of large RCTs 23	Growing — strong recent systematic reviews and trials 4
NHS Recommendation	First-line treatment 1	Emerging; increasingly recognised in clinical practice
Best Suited To	Most people with chronic insomnia as a starting point	People with high sleep anxiety; those for whom rigid protocols amplify fear; those who tried CBT-I without lasting results
Approach to Effort	Structured effort: follow the protocol	Less effort: loosen the grip on controlling sleep

When CBT-I Works Best

CBT-I is the appropriate starting point for most people with chronic insomnia 13. It is particularly effective when:

Insomnia is primarily behavioural — irregular sleep schedules, spending too long in bed, a learned association between the bed and wakefulness
You can tolerate a period of increased sleep pressure during sleep restriction without it significantly escalating your anxiety
The cognitive elements — unhelpful beliefs about sleep — respond well to being challenged and reframed
You want a structured, clear protocol with defined steps

CBT-I tends to produce faster initial results for people where behavioural components are the dominant factor maintaining sleeplessness.

When ACT-I Works Best

ACT-I is particularly valuable when:

CBT-I Has Been Tried but Results Did Not Last — the behaviours improved but anxiety and hypervigilance (an excessive, exhausting alertness to sleep-related signals) remained, and insomnia eventually returned
Sleep Anxiety Is the Dominant Driver — you spend your nights in a state of fear about not sleeping, monitoring every sign of tiredness, catastrophising about the following day
The Effort of CBT-I Amplified the Problem — for some people, strict sleep restriction and rigid rules feel like additional ways to fail at sleep, which increases fear rather than reducing it
You Are Caught in a Cycle of Struggle — the resistance to wakefulness and the desperate effort to control sleep have become the central maintaining factors
Chronic Hyperarousal Is the Core Pattern — a nervous system that has learned to be on high alert at bedtime, regardless of what you consciously believe or intend 5

ACT-I is also often the preferred approach for people who have had difficult experiences with rigid therapeutic frameworks, or for whom “trying harder” at sleep consistently backfires.

Can ACT-I Be Used When CBT-I Has Not Worked?

Yes — and this is one of the most clinically important questions in insomnia therapy.

Many people find themselves in the following position: they followed a CBT-I programme — perhaps a digital version such as Sleepio or Sleepstation, or a brief course of one-to-one therapy — and their sleep improved during the programme, but the improvement did not hold. Or the protocol helped some things but left the underlying fear and anxiety intact.

In this situation, ACT-I is not simply a fallback option. It is addressing a different mechanism. CBT-I may have successfully restructured the behaviours around sleep. What it did not fully address was the psychological war with wakefulness — the hypervigilance, the anticipatory dread, the sense that sleep is something to be won or lost each night 5.

For people in this position, a combined approach — using the behavioural structure of CBT-I where it remains useful, and ACT-I to dissolve the fear response that the protocol did not reach — is often the most complete solution 34.

The Integrated Approach: Why CBT-I and ACT-I Together Go Further Than Either Alone

CBT-I and ACT-I are not competing frameworks. They address different layers of the same problem.

Chronic insomnia almost always has two components:

Behavioural patterns that maintain wakefulness — irregular schedules, spending excessive time in bed, the stimulus association between bed and wakefulness
Psychological patterns — the fear, the vigilance, the effortful attempt to control sleep that keeps the nervous system in a state of perceived threat 5

CBT-I addresses the first layer directly and the second indirectly, through cognitive restructuring. ACT-I addresses the second layer directly. Together, they cover the full picture 34.

This is the approach at the heart of Tracy The Sleep Coach’s practice. CBT-I principles are applied where they serve you as an individual. ACT-I principles are integrated where the fear and struggle response is the dominant pattern. The programme is tailored to what you actually need — not to a fixed protocol applied uniformly.

The goal is not adherence to a protocol. The goal is sleeping — and building the understanding and resilience to keep sleeping independently, for life.

Book a free 20-minute chat to find out whether CBT-I, ACT-I, or a combined approach is the right fit for your situation.

About Tracy Hannigan

Tracy Hannigan is a qualified insomnia therapist with specialist training in both CBT-I and ACT-I. She is a member of the British Sleep Society, the Society for Behavioural Sleep Medicine, and the British Society for Lifestyle Medicine, and is a Featured provider on the international CBT-I Directory (cbti.directory). She works exclusively with insomnia in adults through her Sleep Reboot and Sleep Reframe programmes.

All sessions are delivered online via Zoom, across the UK and worldwide.