Substance-related disorders refer to a range of difficulties involving problems and dependence associated with substance use. These disorders may involve the use of substances such as alcohol, drugs, medications, and tobacco. Substance use can negatively affect daily functioning, health, relationships, and overall quality of life. Examples include:

Substance Use Disorders: A broad term involving loss of control over a substance, impact on daily life, and signs of dependence. Substance use disorders may be linked to alcohol, drugs, opioids, cocaine, marijuana, amphetamines, and other substances.
Alcohol Use Disorder: A disorder involving problems related to alcohol use, including difficulty controlling drinking, impairment of daily functioning, physical health problems, and social difficulties.
Drug Dependence: Associated with regular and uncontrolled use of various drugs (for example, cocaine, heroin, methamphetamine). Dependence is usually characterised by physical and psychological signs of addiction.
Nicotine Dependence: Involves regular, addictive use of nicotine-containing products, especially cigarettes. Nicotine dependence may include both physical and psychological addiction.
Opioid Use Disorder: Involves uncontrolled use of and dependence on opioids (for example, morphine, oxycodone, fentanyl). Opioid dependence can lead to serious health problems and life-threatening situations.

Substance-related disorders usually have a complex aetiology, and a combination of genetic, biological, environmental, and psychosocial factors may play a role. Treatment may include psychotherapy with strategies for coping with addiction, motivational interviewing, support groups, and medication when necessary. Professional help is important in the process of coping with and recovering from substance-related disorders.