Analysis of the synthetic house-tree-person drawing test for developmental disorder

Background: Some patients cannot draw three subjects on the same page during the synthetic house-tree-person drawing test (S-HTP). We call this phenomenon "no synthetic sign". The aim of this study was to clarify the pathological meaning of no synthetic sign and investigate its use for the early detection of developmental disorders at a pediatric primary care center.

Methods: We administered the S-HTP to 283 people who consulted the child psychosomatic medical clinic of Okayama University Hospital in 2007-2012. We diagnosed developmental disability based on DSM-IV-TR criteria and compared findings between the different diagnostic groups.

Results: A total of 241 patients completed the S-HTP (S-HTP group) and 22 patients were not able to complete the S-HTP, but did complete the HTP (an original version of the S-HTP) or tree test (HTP group). Significantly more people in the HTP group had autism spectrum disorder (ASD) compared with the S-HTP group. Full-scale intelligence quotient was significantly lower in the HTP group compared with the S-HTP group.

Conclusions: There were two types of patients with no synthetic sign. The first involved patients with a suspected mental age younger than 5 years 11 months. The second type consisted of patients with ASD. Although drawing ability reflects multiple domains, it may help in early identification of children with developmental problems and facilitate earlier initiation of interventions.