NCIt definition : Maladaptive pattern of drug or alcohol use that may lead to social, occupational,
psychological, or physical problems.;
Alternative definition : NCI-GLOSS: The use of illegal drugs or the use of prescription or over-the-counter
drugs or alcohol for purposes other than those for which they are meant to be used,
or in excessive amounts. Substance abuse may lead to social, physical, emotional,
and job-related problems.;