When Was ACT Therapy Developed? A Plain History

Most people do not come to a therapy approach through its history. They come to it on a hard night, stuck inside their own head, tired of fighting thoughts that will not quiet down. If you have been reading about Acceptance and Commitment Therapy, often shortened to ACT, you are likely not curious about dates. You are quietly asking whether this one might actually help.

This guide answers the history question plainly, because the history is part of why ACT is trusted. But it holds onto the real question underneath it the whole way through: how an approach built over decades of careful research might fit a person who just wants to stop feeling at war with their own mind. We will explain when ACT therapy was developed, who created it, what type of therapy it is, what it is used for, and how to find ACT therapy in Ontario.

When Was ACT Therapy Developed?

Acceptance and Commitment Therapy, or ACT, was developed in the 1980s by psychologist Steven C. Hayes. The first full manual, written with Kirk D. Strosahl and Kelly G. Wilson, was published in 1999. The approach was built slowly, over years of research into how human language and thinking work, which is part of why it is so well studied today.

The early ideas grew out of a simple, uncomfortable observation. The harder a person fights an unwanted thought or feeling, the more it tends to stick around. According to the Association for Contextual Behavioral Science, the professional body Hayes helped found, ACT is rooted in a body of basic science called Relational Frame Theory, and it sits within a broader research tradition rather than coming from a single clinic. That long runway, from quiet lab work to a published manual, is the history of acceptance and commitment therapy in one line.

What Is the History of Acceptance and Commitment Therapy?

The history of acceptance and commitment therapy runs from early 1980s research to the 1999 manual and the decades of trials since. It did not arrive as a finished method. It was tested, refined, and only then written down for other clinicians to use. The acceptance and commitment therapy history is, above all, a history of patience.

To picture where ACT came from, it helps to know what came before it. The first wave of behavioural therapy focused on changing what people do. The second wave, which includes CBT, or cognitive behavioural therapy, focused on changing what people think. ACT belongs to a third wave, sometimes called third-wave behavioural therapy, which focuses on the context around our thoughts and feelings rather than the content of them. The history of ACT therapy is the story of that shift, from arguing with the mind to changing our relationship with it.

Who Created ACT Therapy?

ACT was created by psychologist Steven C. Hayes, who is considered its founder. He developed it alongside Kelly G. Wilson and Kirk D. Strosahl, the three co-authors of the first 1999 ACT manual. It grew out of a research community rather than a single person’s clinic, which is one reason it has been studied so widely.

If you have wondered who developed ACT therapy, or who developed acceptance and commitment therapy, the honest answer names all three. Hayes is the most public face and the ACT therapy founder most people can name, but the work of turning a dense scientific theory into something a person can actually use in a therapy room was shared. Knowing who created ACT therapy, and how many hands shaped it, is part of why clinicians trust the approach. It was not a trend. It was a decades-long effort to understand what it means to be human and in pain at the same time.

What Is Relational Frame Theory?

Relational Frame Theory, or RFT, is the basic science underneath ACT. In plain terms, it studies how humans link ideas together with language, so that a single word or memory can carry a whole weight of feeling. RFT helps explain why we cannot simply think our way out of suffering, and why learning to relate to thoughts differently can help more than fighting them.

You do not need to understand RFT to benefit from ACT, any more than you need to understand engine design to drive. But it matters that ACT has a research foundation under it. The approach was not built on a hunch. It was built on years of work into how the mind actually handles language and meaning.

What Type of Therapy Is ACT?

ACT is a third-wave behavioural therapy. It blends mindfulness, which means paying gentle attention to the present moment, with acceptance of difficult feelings and a commitment to your values. Instead of trying to remove or argue with painful thoughts, ACT helps you change how you relate to them while you keep moving toward what matters to you.

So when people ask what type of therapy is acceptance and commitment therapy, the short answer is an action-oriented one. It is practical, not only reflective. You are not asked to spend months proving a thought wrong. You learn to notice the thought, hold it more lightly, and take a real step in the direction of the life you want anyway. That is what type of therapy is ACT: a method for living alongside hard feelings rather than waiting for them to disappear first.

What Is Psychological Flexibility?

Psychological flexibility is the main goal of ACT. It means being able to stay present with what you are feeling and keep doing what matters to you, even when hard thoughts and feelings show up. ACT does not promise to remove pain. It works to help you carry it without letting it run the whole day.

This is the quiet idea at the centre of the approach. Many of us organize our lives around avoiding discomfort, and the avoidance slowly shrinks the life. Psychological flexibility points the other way. It suggests that you can feel anxious and still go to the thing that scares you. You can feel grief and still call the friend. The feeling and the life do not have to wait for each other.

The Six Pillars of Psychological Flexibility

ACT builds psychological flexibility through six connected skills, sometimes drawn together as a model called the Hexaflex. These are the six pillars of psychological flexibility, and they stay the same whether you are working with a therapist in person or using online therapy in Ontario:

• **Acceptance:** letting feelings be present without fighting them.
• **Cognitive defusion:** seeing a thought as words or pictures passing through, not as absolute truth.
• **Being present:** staying with the here and now instead of replaying yesterday or rehearsing tomorrow.
• **Self as context:** noticing that you are the one observing your life, not the pain itself.
• **Values:** getting clear on what actually matters to you.
• **Committed action:** taking real steps toward those values, even when it is hard.

Cognitive defusion is worth a plain-English note, since it is the term people stumble on. It simply means learning to see a thought as a thought. “I am going to fail” can be held as a sentence the mind produced, rather than a fact about the future. That small distance is often where relief begins.

What Is ACT Therapy Used For?

ACT is used for anxiety, depression, chronic pain, OCD, substance use, and work-related stress, among other concerns. Because it focuses on how a person handles thoughts and feelings rather than on a single symptom, it is flexible. Many people also use it simply to live closer to their values, not only to treat a diagnosis.

So what is acceptance and commitment therapy used to treat, in plain terms? Here is some of what the research and clinical use cover:

• **Anxiety and depression:** learning to make room for hard feelings instead of running from them.
• **Chronic pain:** building a fuller life even when the body still hurts.
• **OCD:** using defusion to loosen the grip of loud, intrusive thoughts.
• **Substance use:** reconnecting with values that give recovery a reason to continue.
• **Stress:** including the high-pressure kind that builds up in demanding jobs.

When people ask what is acceptance and commitment therapy used for over the long run, the most honest answer is quality of life. ACT works less like a one-time fix and more like a set of skills you keep with you. The American Psychological Association has published on ACT and mindfulness for chronic pain, noting a growing evidence base for this kind of approach (APA, 2014).

ACT for Anxiety and Depression

ACT for anxiety and depression takes a different angle from approaches that try to talk you out of a feeling. Instead, it helps you accept the feeling as part of being human, hold the anxious or low thoughts more loosely, and keep taking small steps toward the things you care about. For anxiety, that often means doing the valued thing while the fear is still present. For depression, it often means gentle, values-based action when motivation has gone quiet.

This is also where ACT and CBT often work side by side. Many therapists draw on both, depending on what a person in front of them actually needs.

What Is the Difference Between ACT and CBT?

CBT usually works by testing and reshaping thoughts that seem inaccurate. ACT does not try to change the thought. It helps you accept the thought, see it as just words, and keep acting on your values anyway. CBT is second-wave behavioural therapy; ACT is part of the third wave. Many therapists blend the two.

In the ACT vs CBT conversation, it helps to remember that neither is better in the abstract. They are different tools. Traditional CBT asks, in effect, is this thought true and helpful, and can we make it more accurate. ACT asks, can you let this thought be here, without it deciding what you do next. Some people respond strongly to one approach, some to the other, and many do best with a thoughtful mix. If you are not sure which fits, that is a normal question, and a good one to bring to a therapist directly.

ACT in Primary Care and Trauma Settings

Over the years, ACT has been adapted for different settings. One adaptation is Focused Acceptance and Commitment Therapy, often shortened to FACT, which is built for short, brief sessions. It is sometimes used in primary care, for moments when a person is seeing a family doctor but could use mental health support quickly rather than after a long wait.

Another adaptation is Trauma-Focused Acceptance and Commitment Therapy, sometimes called TFACT. Trauma can make a person want to flee their own body and memories. A trauma-focused ACT approach offers a steady, paced way to face the past while still committing to a future that holds meaning. If trauma is part of what you are carrying, this is worth raising with a clinician, since trauma work needs care and the right pace.

How to Access ACT Therapy in Ontario

If you live in Ontario, you can access ACT therapy online from home. Saalvio offers virtual therapy delivered by registered psychotherapists and registered social workers, and many on our clinical team use acceptance and commitment therapy in their work. You can see our ACT page for more on the approach and how sessions are structured.

In a province this large, getting to care should not depend on where you live or how far you can drive. ACT therapy in Ontario through Saalvio is delivered online, so the support is the same whether you are looking for therapy in Kitchener, therapy in Oshawa, therapy in Sudbury, or anywhere else in the province. Online ACT therapy in Ontario removes the commute and the waiting room, which for many people is the difference between starting and putting it off again.

Before you commit to anything, you can message a registered psychotherapist before you book and ask whatever you need to ask: whether they use ACT, whether they have worked with someone in a situation like yours, whether their approach fits what you are going through. There is no cost and no commitment. Messaging is not therapy by text and it is not crisis support; it is simply a way to ask your questions first. Every Canadian’s first therapy session with a Saalvio clinician is free, so deciding to try ACT is not a gamble on whether the fit will be right.

A note on cost and coverage, since it matters. Saalvio does not bill insurers directly, but sessions with registered psychotherapists and registered social workers are typically reimbursable under most Canadian extended health benefit plans. You receive a detailed receipt to submit to your insurer, and coverage varies by plan, so it is worth confirming the specifics with your own provider.

Is ACT Therapy Evidence-Based?

Yes. ACT is one of the more heavily researched modern talk therapies. According to the Association for Contextual Behavioral Science, there are well over a thousand randomized controlled trials of ACT across a wide range of concerns, and the approach is recognized by major professional bodies as having research support for several conditions.

That research base is part of why clinicians trust it, and part of why we are careful about how we describe it. ACT is well supported. It is not a guarantee. No honest therapy promises a fixed outcome, and ACT, at its heart, is about something quieter than a cure: learning to live a fuller life while making room for the hard parts.

Frequently Asked Questions

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Saalvio Editorial Team

Clinically reviewed by Usman Khan, RP (CRPO #13456)