This refers to a A maladaptive pattern of substance use that results in significant impairment or distress. The term has often been used interchangeably with addiction, though it can also refer more specifically to physiological dependence (the body’s adaptation to a substance).
According to the DSM-IV, substance dependence was diagnosed when three or more of the following occurred within a 12-month period:
Tolerance (needing more of the substance to achieve the same effect or experiencing reduced effects with continued use).
Withdrawal (experiencing symptoms when not using the substance or using it to relieve withdrawal).
Using larger amounts or for longer than intended.
Unsuccessful efforts to cut down or control use.
Spending excessive time obtaining, using, or recovering from the substance.
Neglecting important social, occupational, or recreational activities.
Continuing use despite knowing it causes physical or psychological harm.
In modern diagnostic systems (DSM-5), this term has been replaced by Substance Use Disorder (SUD) to encompass both misuse and dependence within a single continuum.
Sources: Gosnold; Recovery Research Institute