What is "third wave" therapy?

Behaviour therapy was the first wave and cognitive CBT the second; the third wave, including ACT, dialectical behaviour therapy (DBT) and mindfulness-based cognitive therapy, shifts from changing what thoughts say to changing our relationship with thoughts and feelings, with an emphasis on acceptance, mindfulness and values.

Can I do ACT on my own?

Studies show self-guided online ACT helps with anxiety, depression and quality of life, more than waiting does. The free exercises here are a good start; if things persist or are severe, working with a therapist is safer.

How do I find an ACT therapist in Hong Kong?

Look for specific ACT training and membership of a professional body. Further down are TreeholeHK's counsellors and clinical psychologists who use ACT; read their backgrounds before you book.

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Therapy approaches, explained

Acceptance and commitment therapyACT

Q: Why does ACT use so many metaphors and exercises?

Because ACT isn't trying to argue you round; it wants you to experience a different way of being with your thoughts. Lab studies found versions with metaphors and experiential exercises worked better than a rationale alone.

Life holds pain, but pain doesn't have to stop you living well. You don't have to think it away first: you can carry it and still walk, step by step, towards what you care about.

Try a free exercise Find a therapist

What ACT asks us is: do we really have to think it through? Could we accept the painful thought, let it be here, and at the same time know that painful thoughts like this aren't enough to steer our lives?

No need to think it through first: what is ACT?

Have you ever worked it all out, yet the voice saying "I'm going to make a fool of myself" still plays the night before your presentation? Tell yourself not to think about it and it gets louder; tell yourself not to be nervous and your chest tightens. If thinking it through and pushing it down both fail, what is left to try?

1The worldview

Neither chasing thoughts away nor being carried off: open, aware, engaged

Acceptance and commitment therapy (ACT) was created by the American psychologist Steven C. Hayes in the mid-1980s and developed with Kirk Strosahl and Kelly Wilson. Its core is not to think the pain away, but to accept that painful thoughts will come, get clear on what you value, and keep moving forward with the pain along for the ride. In the name, acceptance means letting painful feelings and thoughts be there; commitment means committing to act in the direction you value.^[2,3]

ACT belongs to the so-called "third wave" of behavioural and cognitive therapies. Behaviour therapy was the first wave and cognitive behavioural therapy (CBT), which added thinking, the second; the third wave brings in mindfulness and acceptance, based on "acceptance and mindfulness rather than on direct attempts to modify them" (Dryden, 2017, ch. 8, "Contemporary adaptations, developments, extensions").^[1]

In practice: what does a course of ACT look like?

Now you know how it sees a person and how it works. The next questions: what is it actually like, does it work, and what is it not for?

Put into a therapy room, ACT has no fixed order; your therapist moves between the hexaflex processes to fit you. What follows is a common course, not a required one. Sometimes values come first and defusion follows; for someone in great distress, it may first mean learning not to be trapped by thoughts and to allow yourself to feel bad, and only then turning to values.

1Getting to know you, and consentTalk through what's going on. Therapists often use a short metaphor to show what ACT does, so you can decide whether to try it.
2Count the cost of controlLook back at what you've tried to get rid of the pain: did it help in the short run, and what did it cost over time? This is the creative hopelessness described above, and it prepares the ground for acceptance.
3Practise opening up and noticing

Free ACT exercises

Want to try it yourself first? These free exercises are simpler versions of the skills above, with you step by step.

ACT videos

Episodes are in Cantonese.

A self-guided ACT path

Not ready to see a therapist yet? Start with these six steps at your own pace, one or two a week. The order echoes a course of therapy: understand first, steady yourself, step back from thoughts, then find a direction and take the first step.

Courses

A twelve-hour follow-on for those who know the basics: case work, group design and applying ACT to different difficulties.

Therapists who practise ACT

TreeholeHK's counsellors and clinical psychologists use ACT to fit what you need, alongside other approaches.

ACT's neighbours: what they add

ACT looks after your relationship with thoughts and feelings, and the direction you want to go. Other approaches each answer the questions above in their own way; start here.

Examines what a thought says, finds the blind spot and corrects it. ACT is often seen as a response to it.
Bringing attention to the present without judging. Much of ACT's opening up and noticing is trained through mindfulness.
Also third wave; balances acceptance and change, first developed for people overwhelmed by intense emotions.

Other therapy approaches

FAQ

What's the difference between ACT and CBT?

The deepest difference is how they treat painful thoughts. CBT examines what the thought says, finds the blind spot and corrects it; ACT doesn't debate whether it's true, but accepts it will come, practises stepping back from it and puts energy into what you value. In research, neither has been shown to work clearly better than the other.^[5,14]

Isn't acceptance just giving up?

No. ACT accepts inner thoughts, feelings and memories so you stop spending your strength fighting them; what follows is action towards your values, which is the "commitment" half. Nor does it ask you to put up with a situation that is harming you.^[5]

Why does ACT use so many metaphors and exercises?

Want someone alongside you?

You can do the exercises on your own. When you're stuck, a trained therapist can take you further.

2The method

How is that done? The hexaflex's six processes

With that worldview in place, ACT works through the hexaflex, and every moment of that opening night finds a place in it. It splits the three sides above into six processes: open covers acceptance and defusion, aware covers present-moment contact and self-as-context, and engaged covers values and committed action (marked A, D, P, S, V, C below). The six are not steps but linked facets, and work can start from any of them. The first four are about mindfulness and acceptance, the last four about commitment and behaviour change, with present-moment contact and self-as-context in both. Its opposite is being tied up by your thoughts, unclear about your values and set on not hurting, so that you can't move.^[3,5]

AAcceptanceMake room for unwanted feelings instead of fighting themOpen
DDefusionStep back from a thought: words in your head, not ordersOpen
PPresent momentBring attention back to here and nowAware
SSelf-as-contextThe part of you that notices is bigger than any thought or feelingAware
VValuesGet clear on who you want to beEngaged
CCommitted actionTake a step towards your values, discomfort and allEngaged

One thought, two relationships: the words stay, the distance changes

AHere is that opening night: you're presenting at Monday's team meeting. The night before, a voice in your head says: "I'm going to make a fool of myself."

Hooked by the thoughtA little more flexible

Thought (defusion)

Hooked by the thought"I'm going to make a fool of myself." It feels like a fact, and grows truer the more you think it

A little more flexible"I notice I'm having the thought that I'll make a fool of myself."

Feeling (acceptance)

Hooked by the thoughtOrdering yourself not to be nervous, and getting more nervous

A little more flexibleThe nerves are still there; let them sit in your chest without chasing them out first

Attention (present moment)

Hooked by the thoughtReplaying the disaster in your head all night

Feet on the floor; read the first page of your notes once

3The skills

Seven skills for another way of being with your thoughts

Put into practice, the hexaflex's processes become the skills below. They are grouped by the three sides above (open, aware, engaged), and each serves one hexaflex process. ACT's skills rarely work by argument. Most use mindfulness exercises and metaphors, so you experience another way of being with thoughts and feelings first-hand. Lab studies agree: versions with metaphors and exercises work better than a rationale alone.

Open: defusion and acceptance

Don't argue with thoughts or wrestle with feelings; let them come, and let them go.

Defusion: stepping back from a thought
For that opening "I'm going to make a fool of myself", don't ask whether it is true; practise seeing it as words in your head. Put "I notice I'm having the thought that…" in front of it, give a recurring thought a name, or repeat one word (say, "milk") quickly until it is only sound. In a small experiment, rapidly repeating a word made negative self-thoughts less believable and less uncomfortable than distraction or trying to control the thought.^[9,10]
Try defusion
Hear it in a session
1. Therapist
  You said a sentence keeps playing while you prepare the presentation. What does it say, word for word?
2. Client
  "I'm going to make a fool of myself, and everyone will see I'm not up to it."
3. Therapist
  When it shows up, how strongly does it grip you, 0 to 10?
4. Client
  About 8. It's on my mind all night.
5. Therapist
  Lots of people get thoughts like this before something important. In a way it's trying to protect you from failing. Rather than argue with it, can we try something different?
6. Client
  OK.
7. Therapist
  Let me write it down. (Writes) Now look at it and read it slowly with a few words in front: "I notice I'm having the thought that I'll make a fool of myself."
8. Client
  "I notice I'm having the thought that I'll make a fool of myself…" That's odd. It feels a bit further away.
9. Therapist
  If it was 8 before, what is it now?
10. Client
  Around 6. But I'm still really nervous.
11. Therapist
  It's fine for the nerves to stay; we're not trying to get rid of them. Can I ask: when this thought has hold of you, what do you usually do?
12. Client
  Rework the slides till 2am. Sometimes I just want to call in sick.
13. Therapist
  In the long run, does that take you towards the kind of colleague you want to be, or away?
14. Client
  …Away. I actually want to speak up in meetings.
15. Therapist
  Next time it plays, you can recognise it: "Ah, the 'I'll make a fool of myself' story again." Then ask yourself which way you want to go right now. Would you be willing to try that this week?
16. Client
  OK, though I think it'll still come.
17. Therapist
  It probably will. We're not practising keeping it away; we're practising keeping your hands on the wheel when it comes.
Notice: This illustrates defusion, going back to the voice on the night before the presentation. The therapist first says thoughts like this are common, even protective, and doesn't argue with the content. With permission, the thought goes on paper with "I notice" in front, then comes the question of whether it is useful: does following this thought take you towards or away from what you care about? The thought's grip only drops from 8 to 6 and the nerves stay: the aim is not to make the thought go, but to let it steer less.
Method based on^[3,11]
Acceptance: dropping the rope
First, an honest look: what have you tried to get rid of the painful feeling (like ordering yourself not to be nervous that night)? Did it work in the short run? What did it cost in the long run? ACT calls this creative hopelessness: not despair about life, but giving up on controlling feelings as the way forward. Then practise making room: notice where the feeling sits in your body, breathe around it, let it stay, and keep your energy for what matters.^[5,10,12]
Hear it in a session
1. Therapist
  Over the past few years, what have you tried to stop feeling anxious?
2. Client
  Loads. Avoiding crowds, a drink before bed, self-help books, telling myself not to think about it…
3. Therapist
  Did they help in the short term?
4. Client
  A bit. But it always comes back.
5. Therapist
  And in the long run? What have you missed out on, keeping it away?
Metaphor: passengers on the bus
Your life is a bus moving forward and you are the driver; happy, sad and frightened thoughts and feelings are passengers getting on and off. Some are loud and tell you to turn or stop. If the driver keeps fighting over who gets on and who gets off, the bus never moves; the passengers can't be thrown off, but the wheel stays in the driver's hands, and the bus can carry them along in the direction the driver chooses. The picture shows defusion and acceptance together: thoughts are passengers, and needn't be argued with or thrown off. ACT leans on metaphors like this one: being told "don't cling" lands far less than working it out for yourself from a picture.^[2,10]

Aware: the present moment and the noticing self

Come back to here and now, to a place where you can see your thoughts and feelings.

Present moment: steady yourself in the storm
When emotions hit like a wave, ACT doesn't rush to calm them. First you drop anchor: name what's here, press your feet into the floor and move your body, then look and listen around you, holding both the hard feeling and the room you're in, and choose what to do next. Once you are steady, you have room to use the other skills. Everyday mindfulness practice brings attention back to the present again and again.^[10,11]
Self-as-context: the noticing self
One part of the mind thinks; another part notices. Thoughts, feelings and roles keep changing, but the you that notices has always been there, like the sky behind the weather. From there, "I'm a failure" is a thought being seen, not the whole of you; it is also the place you step back to in defusion. Lab evidence for this process is thinner than for the others, and anyone prone to feeling detached or unreal should practise it with a therapist.^[3,10]

Engaged: values and committed action

Know what you care about, then take a small step towards it, discomfort and all.

Values: goals versus directions
A goal can be met or missed: set "make a million", and a five-figure bank balance spells failure. A value is a direction you can keep following, such as "be someone who looks after my family", and you can take a step towards it today. For the person presenting at the start, what matters may not be the goal of "not looking foolish" but the direction of "speaking up". That is why ACT asks about values first: a value points your actions somewhere, and one "failure" doesn't cancel it. A common exercise splits life into a few areas, writes down who you want to be in each, then checks how close you lived to it this week. With a direction, the next step is to turn it into concrete action.^[3,10,13]
Hear it in a session
1. Therapist
  At work, what do you most want?
2. Client
  A promotion this year.
3. Therapist

The dialogues are illustrative composites, not real clients; skills that stir strong emotion or touch on trauma should be done with a trained therapist.

It helps, but isn't shown to beat other therapies: what the research says

After all those methods, the natural question is whether there is evidence. Research on ACT has grown fast, and you often hear that it beats CBT. The more rigorous reviews paint a plainer picture: ACT helps, but it hasn't been shown to outperform other established therapies. Here is how firm the evidence is, claim by claim.

For chronic pain
The UK's NICE guideline (2021) says ACT or CBT, delivered by trained professionals, can be considered for people aged 16 and over with chronic primary pain. Even the most cautious review of ACT (a meta-analysis, which pools many studies) rated it "probably efficacious" for chronic pain and tinnitus.^[17,21]
Does it help overall?
Dozens of randomised trials (studies that assign people to groups by chance) found ACT helps with anxiety, depression, substance use, chronic pain and more, with a moderate effect. But most compared it with waiting lists or usual care, and many trials were not rigorously run, so the evidence is enough to say it helps, not yet firm.^[14,15,16]
Compared with CBT and other therapies
ACT and CBT show no significant difference, and full therapist-delivered ACT hasn't been shown to beat other established psychotherapies. A minority of analyses favour ACT, but overall the evidence doesn't separate them; many trials are also too small to show the two are truly equal.^{[14,15,16,17]}
Online self-help
An analysis of 53 trials and over 10,000 people found self-guided online ACT improved anxiety, depression and quality of life more than waiting, broadly holding at follow-up; whether it beats other online programmes is unclear.^[20]
The WHO's stress course
The World Health Organization built its Self-Help Plus group course on ACT: recorded audio, led by trained facilitators, for refugees in distress but without a mental disorder. Among Syrian refugees in Turkey, 21.7% had a mental disorder six months later, against 40.7% in the group given enhanced usual care only; but in a similar trial in Western Europe the benefit showed only just after the course, with no prevention at six months. The results disagree, and more research is needed.^[22,23]

Research quality is ACT's weak spot. A 2026 analysis comparing ACT only with other established psychotherapies found many trials did not register in advance what they were testing, were too small to compare two treatments, and often overstated their conclusions. An older dispute: a 2014 review by a single author found ACT trials had not improved in method since 2008 and that ACT was not yet well established for any condition. A group of ACT researchers, including its founder Hayes, then re-checked it, reported 91 factual or interpretive errors touching 80% of the studies and argued it should be set aside. The author published a rebuttal in 2017, and the two sides still disagree. ACT works, but the claim that it works better than other therapies isn't supported yet.^{[16,17,18,19]}

References

1.Dryden, W. (2017). Cognitive-behavioural counselling psychology. In D. Murphy (Ed.), Counselling psychology: A textbook for study and practice (ch. 8). Wiley (BPS Textbooks).
2.Hayes, S. C., Strosahl, K. D., & Wilson, K. G. (1999). Acceptance and commitment therapy: An experiential approach to behavior change. Guilford Press.
3.Harris, R. (2019). ACT made simple: An easy-to-read primer on acceptance and commitment therapy (2nd ed.). New Harbinger. Chapter 1 (free sample from the author). actmindfully.com.au
4.Hayes, S. C. (2004). Acceptance and commitment therapy, relational frame theory, and the third wave of behavioral and cognitive therapies. Behavior Therapy, 35(4), 639–665. doi.org/10.1016/S0005-7894(04)80013-3
5.Hayes, S. C., Luoma, J. B., Bond, F. W., Masuda, A., & Lillis, J. (2006). Acceptance and commitment therapy: Model, processes and outcomes. Behaviour Research and Therapy, 44(1), 1–25. doi.org/10.1016/j.brat.2005.06.006
6.Hayes, S. C., Barnes-Holmes, D., & Roche, B. (Eds.). (2001). Relational frame theory: A post-Skinnerian account of human language and cognition. Kluwer Academic/Plenum. doi.org/10.1007/b108413
7.Hayes, S. C., Barnes-Holmes, D., & Wilson, K. G. (2012). Contextual behavioral science: Creating a science more adequate to the challenge of the human condition. Journal of Contextual Behavioral Science, 1(1–2), 1–16. doi.org/10.1016/j.jcbs.2012.09.004
8.Hayes, S. C., Villatte, M., Levin, M., & Hildebrandt, M. (2011). Open, aware, and active: Contextual approaches as an emerging trend in the behavioral and cognitive therapies. Annual Review of Clinical Psychology, 7, 141–168. doi.org/10.1146/annurev-clinpsy-032210-104449
9.Masuda, A., Hayes, S. C., Sackett, C. F., & Twohig, M. P. (2004). Cognitive defusion and self-relevant negative thoughts: Examining the impact of a ninety year old technique. Behaviour Research and Therapy, 42(4), 477–485. doi.org/10.1016/j.brat.2003.10.008
10.Levin, M. E., Hildebrandt, M. J., Lillis, J., & Hayes, S. C. (2012). The impact of treatment components suggested by the psychological flexibility model: A meta-analysis of laboratory-based component studies. Behavior Therapy, 43(4), 741–756. doi.org/10.1016/j.beth.2012.05.003
11.Harris, R. (2018). ACT questions and answers: A practitioner's guide to 150 common sticking points in acceptance and commitment therapy. New Harbinger. Worksheets and handouts: Dropping anchor: A script; Defusion from barriers to therapy (free from the author). actmindfully.com.au
12.Harris, R. (2009). ACT made simple: An easy-to-read primer on acceptance and commitment therapy. New Harbinger. Introduction and chapters 1–2, including the "ACT in a nutshell" metaphor (free sample from the author). actmindfully.com.au
13.Lundgren, T., Luoma, J. B., Dahl, J., Strosahl, K., & Melin, L. (2012). The Bull's-Eye Values Survey: A psychometric evaluation. Cognitive and Behavioral Practice, 19(4), 518–526. doi.org/10.1016/j.cbpra.2012.01.004
14.A-Tjak, J. G. L., Davis, M. L., Morina, N., Powers, M. B., Smits, J. A. J., & Emmelkamp, P. M. G. (2015). A meta-analysis of the efficacy of acceptance and commitment therapy for clinically relevant mental and physical health problems. Psychotherapy and Psychosomatics, 84(1), 30–36. doi.org/10.1159/000365764
15.Gloster, A. T., Walder, N., Levin, M. E., Twohig, M. P., & Karekla, M. (2020). The empirical status of acceptance and commitment therapy: A review of meta-analyses. Journal of Contextual Behavioral Science, 18, 181–192. doi.org/10.1016/j.jcbs.2020.09.009
16.Gower, T., Styler, Z. R., & Litz, B. T. (2026). Randomized controlled evidence of the efficacy of acceptance and commitment therapy: A systematic review and meta-analysis. Clinical Psychology Review, 128, 102786. doi.org/10.1016/j.cpr.2026.102786
17.Öst, L.-G. (2014). The efficacy of acceptance and commitment therapy: An updated systematic review and meta-analysis. Behaviour Research and Therapy, 61, 105–121. doi.org/10.1016/j.brat.2014.07.018
18.Atkins, P. W. B., Ciarrochi, J., Gaudiano, B. A., Bricker, J. B., Donald, J., Rovner, G., Smout, M., Livheim, F., Lundgren, T., & Hayes, S. C. (2017). Departing from the essential features of a high quality systematic review of psychotherapy: A response to Öst (2014) and recommendations for improvement. Behaviour Research and Therapy, 97, 259–272. doi.org/10.1016/j.brat.2017.05.016
19.Öst, L.-G. (2017). Rebuttal of Atkins et al. (2017) critique of the Öst (2014) meta-analysis of ACT. Behaviour Research and Therapy, 97, 273–281. doi.org/10.1016/j.brat.2017.08.008
20.Klimczak, K. S., San Miguel, G. G., Mukasa, M. N., Twohig, M. P., & Levin, M. E. (2023). A systematic review and meta-analysis of self-guided online acceptance and commitment therapy as a transdiagnostic self-help intervention. Cognitive Behaviour Therapy, 52(3), 269–294. doi.org/10.1080/16506073.2023.2178498
21.National Institute for Health and Care Excellence. (2021). Chronic pain (primary and secondary) in over 16s: Assessment of all chronic pain and management of chronic primary pain (NICE guideline NG193), recommendation 1.2.3. nice.org.uk
22.Acarturk, C., Uygun, E., Ilkkursun, Z., Carswell, K., Tedeschi, F., Batu, M., … Barbui, C. (2022). Effectiveness of a WHO self-help psychological intervention for preventing mental disorders among Syrian refugees in Turkey: A randomized controlled trial. World Psychiatry, 21(1), 88–95. doi.org/10.1002/wps.20939
23.Purgato, M., Carswell, K., Tedeschi, F., Acarturk, C., Anttila, M., Au, T., … Barbui, C. (2021). Effectiveness of Self-Help Plus in preventing mental disorders in refugees and asylum seekers in Western Europe: A multinational randomized controlled trial. Psychotherapy and Psychosomatics, 90(6), 403–414. doi.org/10.1159/000517504