across time is also reflected by reductions or increases in the fr equency and/or dose of
substance use, as assessed by the individual’s  own report, report of knowledgeable others,
clinician’s observations, and biological testing. The following course specifiers and descrip-
tive features specifiers are a lso available for substance use di sorders: “in early remission,”
“in sustained remission,” “on maintenance th erapy,” and “in a cont rolled environment.”
Definitions of each are provided within respective criteria sets.