Parent question

Does speech therapy work?

Published 21 October 2026 · Updated 21 October 2026

The short answer

For many children, yes. Reviews of randomized trials have found speech and language therapy effective for speech sound difficulties and for expressive vocabulary, with less evidence for difficulties understanding language. Results vary from child to child, and how often therapy happens, whether parents are involved, and using the right approach for the difficulty all matter.

What the research shows

A Cochrane review of 25 randomized trials found therapy effective for speech sound (phonological) difficulties and expressive vocabulary, with mixed results for grammar and less evidence for receptive language. Children treated by trained parents did about as well as those treated by clinicians (Law, Garrett & Nye, 2003).
A meta-analysis by the same team suggested therapy lasting more than 8 weeks may be one factor in good outcomes (Law, Garrett & Nye, 2004).
For young children aged 18 months to 5 years, a meta-analysis of 18 studies found that interventions delivered by trained parents had a significant positive effect on both understanding and using language (Roberts & Kaiser, 2011).
For preschool stuttering, a trial of 54 children found the Lidcombe Program reduced stuttering to 1.5% of syllables at 9 months, against 3.9% without treatment (Jones et al., 2005). A 2021 Cochrane review of stuttering treatments rated the overall evidence as very low certainty (Sjøstrand et al., 2021).
For childhood apraxia of speech, a 2026 meta-analysis of 25 studies found large improvements on practised words and moderate improvements on words that weren’t practised (McCabe et al., 2026).

These are averages across many children, with wide variation, and some reviews are older or rest on low-certainty evidence. “Evidence suggests” is the honest way to put it.

What makes therapy more likely to help

How often it happens. In a trial of 54 preschoolers given the same 24 sessions, three a week led to more progress than one a week (Allen, 2013).
Practice at home. In ASHA’s outcome registry, 50% of children with severe speech sound disorders who had 21 to 30 sessions plus a home program made significant progress in being understood, compared with 33% without a home program, and 70% with twice-weekly sessions plus a home program (ASHA NOMS, 2024). That’s observational data, not a trial.
Starting earlier. In the same registry, preschoolers improved twice as much in how well they were understood as 12 to 14-year-olds (ASHA NOMS, 2024).
The right approach. Different difficulties need different therapy, which is why an evaluation by a speech-language pathologist (SLP) comes first. See what happens at a speech evaluation.

How you’ll know it’s working

Ask your child’s SLP what the goals are and how they’ll measure progress. ASHA describes ending therapy as a decision based on data, like progress toward goals, rather than on age or time in therapy. Keeping a simple practice log helps you see progress too.

Questions parents ask

Is speech therapy worth it?

For many children, research shows real benefits, especially for speech sounds and expressive vocabulary. Results vary, so ask your SLP what progress to expect and how it will be measured.

Does speech therapy work for toddlers?

For late-talking toddlers, a meta-analysis found that interventions delivered by trained parents improved both understanding and using language. See late talker or speech delay.

Why isn’t therapy working for my child?

Common reasons include sessions that are too infrequent, little practice between sessions, or an approach that doesn’t fit the difficulty. Talk to your SLP about frequency, home practice and goals.