DSM-5 substance-use disorders severity

Substance-use disorders occur on a continuum of severity, ranging from mild to severe, according to the number of diagnostic criteria that an individual case satisfies.^[1] The severity of a substance-use disorder can change over time, reflected by change to the severity as defined above, or by changes to the frequency or dose of a substance an individual takes.^[1] The DSM-5 also allows use of the following disease course specifiers for substance-use disorders: ‘in early remission’, ‘in sustained remission’, ‘on maintenance therapy’, and ‘in a controlled environment’.^[1]

Reference:
[1] American Psychiatric Association (APA). Diagnostic and Statistical Manual of Mental Disorders, 5^th edition. American Psychiatric Association, 2013.