Sand tray therapy has been used in the treatment of a wide variety of mental health problems in children, adolescents, and adults since the 1920s, but attempts to demonstrate its value have been limited largely to qualitative case studies. This study used a more rigorous design, a single-case analysis with multiple baselines of varying lengths across participants, to determine if sand tray therapy by itself can have an effect in reducing symptoms of depression in young people aged 11 to 14. As a largely non-verbal therapy focusing on client strengths and available resources, sand tray therapy can be enjoyable and appealing to this age group. It incorporates elements of positive psychology, allowing clients to assert control and to engage in a complex creative process that may enhance feelings of competency and self-worth.

Four participants were enrolled in the study and symptoms were assessed with several standardized paper-and-pencil questionnaires given to participants and their mothers. Primary data on depressive symptoms was collected with a five-question survey that each participant answered every other day by telephone. The baseline was randomly varied for each participant and ranged from 6 to 18 days. Assessment with the five-question survey continued on the same schedule throughout the course of treatment, which consisted of once-weekly sand-tray sessions for 12 to 14 weeks. At the end of treatment, symptoms were again assessed with the same battery of questionnaires. Three of the four participants showed overall improvement in depressive symptoms as measured both by the five-question survey and by standardized instruments, although improvement did not follow the hypothesized pattern of steady and stable gains. Examination of the therapy process in detail revealed individual differences in the ways in which participants engaged in the therapy. The study shows some benefit may be obtained in using sand tray therapy with young adolescents suffering depressive symptoms. Implications of the study in the treatment of adolescents as well as in the study of sand tray therapy process are discussed.