Sand tray therapy has a growing evidence base, but it’s not yet considered a well-established, evidence-based treatment in the way that cognitive behavioral therapy or EMDR are. The research so far is promising, with studies consistently showing improvements across multiple conditions, particularly in children. However, many of these studies have methodological limitations: small sample sizes, lack of comparison groups, and few objective outcome measures. What exists is encouraging enough that clinicians use it widely, but the field still needs larger, more rigorous trials.
What the Research Shows So Far
Every published study on traditional sand-based therapy has reported significant improvements in the groups receiving treatment. That’s a notable pattern. But “significant improvements” in small studies without strong comparison groups is a different thing than the kind of robust evidence that gets a therapy listed in clinical practice guidelines. The most common weaknesses across the research are small sample sizes (sometimes as few as 12 people per group), missing control groups, and reliance on subjective rating scales rather than objective measures.
That said, some of the findings are hard to dismiss. A systematic review published in Frontiers in Pediatrics pooled data from multiple studies on children with autism spectrum disorder and found a large treatment effect for improving social communication skills. The review recommended individual sessions once a week for 22 to 28 weeks as the most effective approach for that population. A study on children at risk for ADHD found that group sandplay in a school setting significantly reduced anxiety, depression, physical complaints, social immaturity, and rule-breaking behavior compared to a control group.
Sandplay Therapy vs. Sandtray Therapy
These two terms sound interchangeable, but they refer to different approaches with somewhat separate evidence bases. In sandplay therapy, which follows the tradition developed by Dora Kalff and rooted in Jungian psychology, the therapist takes a passive role. They observe while the client builds scenes in the sand without direction or interpretation during the session. In sandtray therapy, the therapist actively guides the process, sometimes asking questions, suggesting themes, or directing the play.
Most of the published research blends these approaches or doesn’t clearly distinguish between them, which makes it harder to evaluate either one independently. When you’re reading about evidence for “sand therapy,” it helps to know which version was actually studied. Both appear in the literature, and both show positive results, but they work differently in practice.
Evidence for Anxiety and Depression
The strongest individual demonstration of sand therapy’s effect on anxiety comes from a case study highlighted by the American Psychological Association. A 23-year-old woman with generalized anxiety disorder received 18 one-hour sandplay sessions over nine weeks. Before treatment, she went through a waiting period where her anxiety scores didn’t budge. After the sandplay sessions, her scores on two standard anxiety scales dropped from the severe range to the normal range.
What made this study especially interesting was the brain imaging component. Scans showed that a key brain metabolite in her thalamus (a region involved in processing sensory and emotional information) was below healthy levels before treatment and returned to normal range afterward. This suggests sandplay may do more than just reduce symptoms on a questionnaire. It may produce measurable changes in brain function, particularly in the systems that process emotions below conscious awareness.
This is a single case study, so it can’t prove sandplay works for everyone with anxiety. But it’s the kind of finding that builds a case for larger trials.
Why It Works for Trauma and Nonverbal Processing
Sand therapy’s strongest theoretical argument is also its most practical one: it doesn’t rely on talking. Traditional talk therapy requires you to put experiences into words, which is exactly what many trauma survivors, young children, people with disabilities, and those with language barriers struggle to do. Sand therapy shifts the focus to a physical, visual process. You build a scene, and the scene communicates what words might not.
This is why sand-based approaches have been called one of the most effective ways to work with children and adolescents who have experienced trauma. For young kids especially, the developmental capacity for verbal reflection simply isn’t there yet. Sand therapy meets them where they are. It’s also used with adults dealing with post-traumatic stress, migration-related distress, and cognitive or developmental disabilities where conventional psychotherapy methods hit a wall.
What a Session Looks Like
Sessions typically last about 50 minutes, the same as a standard therapy appointment. The therapist provides a shallow rectangular tray filled with sand and a collection of miniature figures organized into categories: people, animals, fantasy figures, houses, bridges, fences, transportation, religious or spiritual symbols, natural objects like rocks and shells, and abstract or miscellaneous items. The variety matters because it gives you a wide symbolic vocabulary to express inner experiences.
You arrange the figures in the sand however you want, sometimes with guidance from the therapist and sometimes freely. The sand itself can be shaped, molded, or dampened. Over a series of sessions, patterns and themes tend to emerge in the scenes you create, and these become material for therapeutic work. For children with autism, research suggests the most effective schedule is once per week for roughly five to seven months. For other conditions, the duration varies, but most studies use at least 10 sessions.
Therapist Training and Credentials
The International Society for Sandplay Therapy (ISST) sets the standard for formal certification in the Kalffian sandplay tradition. Becoming a certified member requires a minimum of 100 hours of specialized training seminars, plus at least 80 hours of supervised clinical work with at least two different teaching members. Of those 80 supervision hours, at least 30 must be individual (one-on-one) rather than group supervision. Jungian analysts who are already credentialed through the International Association for Analytical Psychology can qualify with a reduced requirement of 60 training hours and 40 supervision hours.
Sandtray therapy (the more directive version) doesn’t have a single equivalent credentialing body, though several organizations offer certificates. If you’re considering this type of therapy, asking a therapist about their specific training in sand-based methods is reasonable. The quality of the therapeutic relationship and the therapist’s skill level matter at least as much as the technique itself.
The Bottom Line on Evidence
Sand tray therapy sits in a middle ground that’s common for newer or niche therapeutic approaches. The existing studies consistently point in a positive direction, with real symptom improvements across anxiety, depression, behavioral problems in children, social communication in autism, and trauma-related distress. Some of these findings include objective measures like brain imaging, not just self-reported questionnaires. But the research base is still relatively small, and many studies lack the rigorous design (large randomized controlled trials with active comparison treatments) that would elevate sand therapy to the “well-established” category.
It is evidence-based in the sense that published research supports its use. It is not yet evidence-based in the stricter sense that major clinical guidelines recommend it as a first-line treatment for any specific condition. For many people, especially children, trauma survivors, and those who struggle with talk therapy, it remains a credible therapeutic option with a logical mechanism and a growing body of supportive data.