SDMT - Symbol Digit Modalities Test

by Aaron Smith, PhD

 

Purpose: Screen for organic cerebral dysfunction

Age: 8 through to 78 yrs
Admin: Individual or group

Time: 5 minutes

 

Brief and easy to administer, the SDMT has demonstrated remarkable sensitivity in detecting not only the presence of brain damage, but also changes in cognitive functioning over time and in response to treatment. It is an economical way to screen apparently normal children and adults (ages 8-78 years) for possible motor, visual, learning, or other cerebral dysfunction.

The SDMT involves a simple substitution task. Using a reference key, the examinee has 90 seconds to pair specific numbers with given geometric figures. Because examinees can give either written or spoken responses, the test is well suited for use with individuals who have motor disabilities or speech disorders. Because it involves only geometric figures and numbers, the SDMT is relatively culture free as well and can be administered to individuals who do not speak English. The SDMT AutoScore™ Test Form simplifies scoring.

The SDMT Manual documents the test's effectiveness in a wide range of clinical applications including differentiation of brain-damaged from psychotic patients; differentiation of organic from depressive disorders; early detection of senile dementia and Huntington's disease; differential diagnosis of children with learning disorders; early identification of children likely to have reading problems; assessment of change in cognitive functioning over time and/or with therapy in individuals who have traumatic, vascular, neoplastic, and other brain insults; and assessment of recovery from closed-head injury