ACT, CBT or something else? Therapy is more than an acronym

What the recent ACT review found

A 2026 systematic review and meta-analysis examined 34 randomised trials of full-model Acceptance and Commitment Therapy. The researchers included therapist-delivered, multi-session ACT that addressed its core processes and compared it with other credible psychotherapies rather than relying mainly on waiting-list or minimal-control comparisons, which makes the result more relevant to the ordinary clinical question of whether ACT offers an advantage over another reasonable treatment.

ACT was not superior to those other therapies on mental or behavioural health outcomes, with a pooled difference that was close to zero. That result does not establish that ACT is ineffective, and it does not establish that every therapy will work equally well for every person or every problem. It tells us that the current trials do not justify claiming that ACT works better than other established psychological treatments.

The review also found weaknesses in the evidence base that make strong conclusions more difficult. Many studies had not preregistered their main outcomes and hypotheses, some were too small to detect modest differences between treatments, intent-to-treat analysis was not always used, and the authors identified examples where the conclusions went further than the results allowed. Their additional analysis of possible equivalence was exploratory, so the most defensible reading is that ACT remains a credible way of doing therapy without evidence that it should be placed above the field.

What a treatment model changes

A treatment model gives the clinician a theory about what is keeping a problem going and a set of actions that may change it, which is why therapy should have more structure than a conversation in which any technique seems as good as another. For someone with obsessive-compulsive disorder, exposure and response prevention may be central because rituals and reassurance keep the threat system learning the same lesson. For persistent panic, fear of bodily sensations and the escape behaviours that follow may become direct treatment targets, while trauma work may involve memory processing whose timing is shaped by assessment, preparation and present-day safety.

The model matters because it changes what we do in the room and between sessions, although the label alone tells us very little about the quality or focus of that work. Two therapists may both say they provide CBT while one mainly discusses thoughts and the other carefully tests avoidance through behavioural experiments. Two clinicians may use ACT while working quite differently with willingness, attention, values and behaviour, and those differences may matter more to the client than the name on the treatment plan.

I tend to think of a therapy model as a set of tools, with clinical formulation providing the reasoning needed to decide what requires attention, which tool fits that task and whether it is producing the change we expected. Brand loyalty is not formulation.

Where treatment fit matters

Clinicians sometimes use “fit” as a vague promise that therapy will be personalised, so I use the word carefully. A 2025 meta-analysis of 16 randomised studies did not find convincing evidence that more personalised psychological treatment produced better symptom, smoking cessation or treatment-process outcomes. Most included studies had at least some risk-of-bias concerns, and the authors concluded that better research is needed to establish which forms of personalisation help whom.

There is separate evidence that client preference has modest links with treatment satisfaction, completion and clinical outcome. A 2025 update covering 46 comparisons for clinical outcomes found significant preference effects, which gives us a reason to ask what a person expects, fears and prefers when there are credible choices, while still recognising that preference cannot replace attention to safety, diagnosis or treatment evidence.

A recent review of therapist effects estimated that individual therapists account for some variation in outcomes, commonly around 5 to 8 per cent. Interpersonal skills had the most consistent association with outcome, although the review found substantial weaknesses in the underlying research, and these findings remain associations across studies rather than proof that warmth or experience alone causes a better result.

In a session, treatment fit becomes more concrete through questions about whether we are working on the problem that is most disruptive now, whether we can explain how the proposed treatment is meant to change it, whether the pace allows enough safety without turning preparation into indefinite avoidance, and whether the person can say when an exercise feels irrelevant, shaming or too much. Regularly checking change matters because a formulation is a working explanation, not a verdict that should remain untouched once therapy has begun.

Consider someone who has both a trauma history and panic attacks. If the immediate loop is fear of bodily sensations followed by escape, interoceptive exposure may deserve attention even though trauma is part of the wider history. Another person may be seeking repeated reassurance about harm, in which case spending months discussing why they worry without addressing the reassurance cycle may leave the main mechanism untouched. The formulation gives us a reason to begin in one place and to review that decision when the evidence from therapy points elsewhere.

Ask for the reasoning, not just the label

A psychologist should be able to explain what they think is happening, why a particular approach has been suggested, what the work is likely to involve and how progress will be judged. There may be uncertainty, especially early in treatment, but that uncertainty can be spoken about plainly rather than hidden behind professional confidence or the name of a therapy model.

Useful questions include what the therapy is targeting, why this method fits that target, what you will be asked to practise and what will change if progress stalls. Asking these questions is part of shared clinical work, because a treatment plan is more useful when both people understand its rationale and can identify when it needs to be adjusted.

If, after several sessions, you still cannot tell what the work is targeting, asking for a review is part of therapy rather than a criticism of it.