12.1 : 药物滥用和成瘾：药理现象

Drug abuse is the harmful overuse of substances, often leading to addiction or compulsive drug-seeking behavior.

Drugs of abuse typically stimulate the brain's mesolimbic system, releasing dopamine and causing pleasurable effects. Repeated use builds tolerance, necessitating higher drug doses for the same effect.

Continued drug use can lead to physical dependence and withdrawal symptoms upon cessation.

Various factors influence drug abuse. Drug variables like potency, administration route, and onset rapidity increase abuse risks.

Host variables include genetic predisposition and psychiatric disorders. Environmental variables, such as availability, social influences, and peer pressure, also play a significant role.

Drugs interact with our bodies in diverse ways. Some activated G_io -coupled receptors, others alter ion flow across cell membranes, and some bind to biogenic amine transporters, impacting neurotransmitter reuptake.

Understanding and targeting these mechanisms is crucial for effective drug addiction treatments.