This refers to a medical condition resulting from repeated use of one or more substances, leading to clinically significant impairments in health, social functioning, and self-control. According to the DSM-5, SUDs are diagnosed based on cognitive, behavioural, and psychological symptoms that indicate a loss of control over substance use.
SUDs exist on a spectrum from mild to severe and may range from temporary to chronic. They typically develop gradually with repeated use, resulting in changes to brain systems that regulate reward, stress, motivation, and executive functioning (e.g., decision-making and self-control).
Several factors, such as the type of substance, genetic predisposition, and the frequency and duration of use, affect the risk and speed of developing an SUD.
Notably, the DSM-5 replaced older terms like substance abuse and substance dependence with a unified diagnosis of substance use disorder, categorised by severity (mild, moderate, or severe).
Severe SUDs are often referred to as addictions.
Sources: SAMHSA_NCBI; Recovery Research Institute; HRB