可卡因May Play Role in User's Depression

许多长期可卡因用户患有抑郁症。抑郁症报告的抑郁症慢性可卡因施虐者are significantly higher than in the general population.

试图确定为什么可卡因用户体验萧条和其他疾病，科学家认为它与药物对脑细胞的损害有关，让用户在可卡因时感到高的脑细胞。

多巴胺神经元不安

When cocaine is used it increases the level of dopamine in the brain, creating the high that users feel, but prolonged use of the drug reduces the dopamine levels, making it harder for the user to experience positive feelings.

"This is the clearest evidence to date that the specific neurons cocaine interacts with don't like it and are disturbed by the drug's effects," says Karley Little, M.D., associate professor of psychiatry at the University of Michigan Medical School and chief of the Ann Arbor Veterans Affairs Medical Center Affective Neuropharmacology Laboratory. "The questions we now face are: Are the cells dormant or damaged, is the effect reversible or permanent, and is it preventable?"

长期可卡因用户研究

很少和同事研究了在35个长期可卡因用户和35名非用户的尸体术中获得的脑组织样品。它们分析了多巴胺和蛋白质VMAT2的组织，该组织在多巴胺转运蛋白中发现。

Urine or serum samples were also analyzed for the presence of cocaine, opioids, antidepressants, and antipsychotic medications. A person close to each individual was interviewed about the individual's substance abuse, alcoholism, and symptoms of personality and mood disorders.

解释可卡因戒断症状

Researchers found that cocaine users had lower concentrations of dopamine and VMAT2 in their brains than did non-users. Additionally, cocaine users suffering from depression had lower levels of VMAT2 than those who were not depressed. Depressed cocaine users have greater difficulty maintaining work and family, have a more difficult time quitting drug use, are at a greater risk of dropping out of treatment, and are more likely to commit suicide.

可卡因改变了大脑

Little and colleagues were uncertain whether dopamine cells had been destroyed or just dysregulated by cocaine use, and if such changes could be reversed.

“我们可以看到大脑试图调节多巴胺系统的结果，以应对可卡因使用，试图减少通过减少在囊泡中收集它的能力而释放的多巴胺量，”较少说。“但我们也可以看到真正的伤害或死亡dopamine neurons。无论哪种方式，这都突出了这些神经元的脆弱性，并显示了可卡因使用可以创造的恶性循环。“

Further efforts at clarifying the detrimental effects of cocaine on brain cells may help in the development of effective treatment interventions and pharmacotherapies, the researchers suggested.

该研究部分由国家药物滥用研究所资助。