Substance use disorder

Substance use disorder is a condition where a person has difficulty controlling their use of drugs or alcohol despite harmful consequences. It primarily affects the brain's reward system, leading to strong cravings and compulsive behavior. This disorder impacts the nervous system by altering brain chemistry and function. People with this condition often experience withdrawal symptoms when not using the substance and may develop tolerance, needing more to achieve the same effect. It can cause serious health problems, including mental health issues, physical illness, and social difficulties. The disorder affects overall well-being and can disrupt daily life and relationships.

Substance use disorder is a chronic brain disorder characterized by the compulsive use of psychoactive substances despite adverse consequences. It involves dysregulation of the mesolimbic dopamine pathway, which mediates reward and reinforcement. The core pathology includes neuroadaptations that lead to tolerance, withdrawal, and craving. The disorder is caused by repeated exposure to substances such as alcohol, opioids, stimulants, or sedatives, which alter neurotransmitter systems. Clinically, it manifests as impaired control over substance use, social impairment, risky use, and pharmacological criteria like tolerance and withdrawal. It is a major cause of morbidity and mortality due to overdose, infectious diseases, and psychiatric comorbidities.