Letters to the Editor amicable discussion with the substance "user" might help to elicit the cause for reporting substance use when the drug screen is negative.Thus, one could use UDSs selectively or randomly during intake interviews for addiction services. One should be cognizant of potential false positive and false negative reports, 2 issues surrounding an unadulterated collection of samples, and the availability of reasonably accurate testing methods. In select sensitive circumstances, repeat testing or testing using very specific methods (like spectrometry or high-performance liquid chromatography) can be used. Nonetheless, carefully directed UDSs and empathetic utilization of their results can lead to better-directed care of individuals with substance use disorders.