This refers to the process by which the introduction of a pleasurable or rewarding stimulus increases the likelihood of a behaviour being repeated. In the context of substance use, this occurs when drug use produces desirable effects, such as euphoria, relaxation, or heightened alertness, that strengthen the motivation to use the substance again.
This mechanism plays a central role in the development of addiction, as the brain’s reward system learns to associate drug use with pleasurable outcomes, reinforcing continued use despite potential negative consequences.
Sources: SAMHSA_NCBI