Figure 2.

Digit Symbol Substitution Test (DSST) (performed 8 hours post dose) – a measure of attention and sedation. Subjects are presented with rows of blank squares paired with randomly assigned numbers. In a defined time period, they are required to substitute digits with a different, corresponding nonsense symbol, the key to which is provided: no significant difference in DSST scores between groups (SEM = standard error of the mean). With permission from Pharmacotherapy.[23] Copyright 2005, Pharmacotherapy Publications.