No abstract

The Symbol Digit Modalities Test is a substitution task that is the inverse of the Digit Symbol Test. The familiar task of filling numbers in boxes, and the availability of an oral administration, make this a popular screening instrument for brain impairment. Normative data were previously reported for a variety of clinical groups, but complete information on non-clinical samples across age, education, gender, and socioeconomic status is limited. The present study examines the performance of a community-dwelling control sample across age, education, gender, and income groupings. In a multivariate model, these four variables did not impact test performance. These results support the utilization of the SDMT as a robust screening test for adult neuropsychological impairment.

This is, to our knowledge, the first study that prospectively examines the relationship between sleep problems and early onset of alcohol use, a marker of increased risk for later alcohol problems and alcohol use disorders. Moreover, early childhood sleep problems seem to be a robust marker for use of drugs other than alcohol. Implications for the prevention of early alcohol and other drug use are discussed.