Statistical models to estimate level of psychological disorder based on a computer rating system: An application to dementia using structured mandala drawings

The mandala has been widely accepted as an effective art therapy tool to determine a client's emotional or psychological status and to treat associated disorders. The authors apply a computer system to estimate participants’ levels of dementia based on the elements in the structured mandala drawing. A regression model was formulated whose dependent variable is the level of dementia scored by a test, and the independent (explanatory) variables are the elements in the structured mandala. These dependent variables were analyzed with the computer system. The consistency between the test score and the computer system's estimated score was verified statistically. Also, another regression model was formulated to estimate the probability of severe dementia. This model classified the level of dementia into one of two categories, severe or not, by representing it as an indicator dependent variable. In both models, the important independent variables were selected by stepwise regression, and the relative magnitudes of their effects were compared by standardized regression. The system was found to provide art therapists with useful information on the stages of a patient's advancing dementia. These methods were also determined to be applicable to estimating the level and the severity of other psychological disorders.