How Talking Therapy Works: What the Evidence Says

If you have never had therapy, you might wonder whether it actually does anything. Decades of research show that psychological therapy can be an effective treatment for many people. Here is what the evidence says, and why.

If you have never had therapy and are considering it, you might quietly wonder whether it actually does anything. The image of talking to a stranger about your problems for an hour does not, on the face of it, look like a serious intervention. And yet decades of research consistently show that psychological therapy works for a wide range of mental health conditions. This post explains what the evidence shows and why it works.

What the research actually shows

Psychological therapy has been studied extensively over the past sixty years. The evidence base now includes thousands of randomised controlled trials, systematic reviews, and meta-analyses across most common mental health presentations.

The headline finding is that evidence-based psychological therapy produces meaningful improvements for most people who engage with it. The effect sizes for therapy in conditions like depression, anxiety, post-traumatic stress disorder, obsessive-compulsive disorder, and many others are comparable to the effect sizes of well-established medical treatments for the same conditions.

This does not mean therapy works for everyone, or works equally for every condition. It does mean that therapy is, by any reasonable definition, an effective treatment.

Why people doubt that it works

Several features of therapy make people sceptical even in the face of strong evidence.

It looks like conversation. Most other things that produce measurable change in our lives (medication, surgery, exercise) involve obviously medical or physical interventions. Therapy is two people talking, which does not look like treatment.

The mechanism is not obvious. Most people can intuit how a medication or a surgery might change their body. The mechanism by which a therapeutic conversation changes someone's mood or thinking is less obvious from the outside.

The results take time. Therapy rarely produces immediate, dramatic improvements. The changes accumulate over weeks and months, and the contrast between week one and week one is often less obvious than the contrast between week one and week ten.

The therapist does not seem to be doing much. From the outside, a therapist often appears to be mostly listening, asking questions, and occasionally offering reflections. The work being done is largely invisible to the observer.

How therapy works

Several mechanisms appear to contribute to therapy's effectiveness, and most evidence-based therapies draw on a combination of them.

The therapeutic relationship itself. The single most consistent finding in psychotherapy research is that the quality of the relationship between the client and the therapist predicts outcomes more strongly than the particular approach used. A safe, attentive, non-judgmental relationship is itself a kind of corrective experience, particularly for people whose early relationships did not provide this.

Insight and self-understanding. Therapy provides space to notice patterns in your own behaviour, thinking, and relationships that are usually too close to see. Once a pattern is visible, it becomes possible to change it.

Skill-building. Most evidence-based therapies involve teaching specific skills, including cognitive techniques for working with unhelpful thinking, behavioural techniques for changing patterns, and emotion-focused skills for regulating distress.

Behavioural change. Therapy often involves trying new behaviours between sessions, gradually expanding the range of what you can do, tolerate, or approach. This is particularly important in conditions like anxiety, where avoidance maintains the problem.

Exposure to feared experiences. For anxiety disorders and trauma, evidence-based therapy involves gradual, supported contact with the situations, memories, or experiences that have been avoided. Doing this in the safety of the therapeutic relationship allows the system to learn that these experiences can be tolerated.

Reorganising the story. Many people come to therapy with implicit stories about themselves and their lives (I am not good enough, I am unlovable, I cannot trust anyone). Therapy helps to examine these stories, test them against actual evidence, and develop more accurate and useful ones.

Which therapies have the strongest evidence

Several therapeutic approaches have particularly strong evidence bases for common presentations.

Cognitive behavioural therapy (CBT) is the most-studied approach overall, with strong evidence for anxiety disorders, depression, PTSD, OCD, eating disorders, and many other conditions.

Acceptance and commitment therapy (ACT) has growing evidence across a wide range of presentations and is particularly useful where rigid thinking patterns are part of the problem.

Schema therapy has evidence for personality difficulties and long-standing patterns of relating.

Eye movement desensitisation and reprocessing (EMDR) has strong evidence for PTSD and trauma.

Interpersonal therapy has evidence for depression and grief.

Dialectical behaviour therapy (DBT) has evidence for emotion regulation difficulties and borderline personality disorder.

The right approach depends on what you are working with. A good therapist will explain what they propose to do and why, and will adjust if it is not working. At Ivy Psychology, our psychologists draw on a range of evidence-based approaches, matched to the person and the presentation rather than applied as a one-size-fits-all method.

What therapy does not do

Therapy is not magic. It does not erase difficult experiences, eliminate all distress, or guarantee that life will be free of struggle. It also does not work in the same way for everyone, and some people find a particular therapist or approach unhelpful even when others find it transformative.

What therapy does is provide a structured, evidence-based process for working with the patterns that are causing problems, with a trained professional whose entire job is to help you. The work is yours; the support is theirs.

A practical note

The single biggest predictor of whether therapy will help a given person is fit. If you try therapy and it does not click, that is not necessarily a sign that therapy will not work for you. It may be a sign that this particular therapist or approach is not the right match. Trying another clinician or another approach is reasonable.

If you are considering therapy and are not sure where to start, a conversation with your GP is a sensible first step. A GP can help you think through what kind of support might fit and write a Mental Health Treatment Plan for Medicare-subsidised sessions.

If you would like to talk to one of our psychologists about what therapy could look like for you, you are welcome to get in touch.