What causes addiction, and why is it so hard to treat? - Judy Grisel

翻译人员: Jinnie Sun 校对人员: Gia Hwang

As of 2021, more than 36 million people worldwide

截至 2021 年， 全球约有超过 3600 万人

were estimated to be experiencing substance abuse disorder.

有物质使用障碍。

This condition spans a spectrum of patterned drug use

这种情况包括了一系列药物使用模式，

that causes issues in a person’s life.

会给人的生活带来问题，

At the more severe end of the spectrum is substance addiction.

其中更严重的是物质成瘾。

To understand why some people are more susceptible to addiction

为了理解为什么有些人更容易成瘾，

and why it can be so difficult to treat,

以及为什么成瘾如此难以治疗，

let’s take a look at how addictive drugs affect the body.

让我们来看看成瘾性药物 是如何影响人体的。

When someone repeatedly uses an addictive substance,

当人反复使用成瘾物质时，

their brain may adjust to account for its regular presence.

他们的大脑可能会自我调整

以适应这种物质的经常存在，

This is called tolerance; it diminishes the drug’s effect

这被称为耐受性。

它使得药物的作用降低，

and means more is required to produce the same experience.

而且意味着需要更大的量 才能产生相同的体验。

Alcohol, for instance, increases the transmission of chemical messengers

例如，酒精会增加一些化学信使的传递，

like endorphin and GABA,

如内啡肽和GABA（一种神经递质），

which promote sensations of pleasure and calmness.

它们促进愉悦感和平静感的产生。

When someone uses alcohol frequently, their brain will adapt to its presence.

当人经常饮酒时，

大脑会适应酒精的存在，

So when they don’t use it, their brain receives fewer signals

因此当不饮酒时，

大脑接收到的那些愉悦

from those pleasure- and calm-inducing neurotransmitters,

和镇静神经递质信号就会减少，

which impacts their energy and mood.

这会影响他们的精力和情绪。

In addition to the unique effects each addictive substance has,

除了每种成瘾物质自身独特的作用外，

all of them alter the release of dopamine

所有这些物质都会改变大脑中

in a brain region called the nucleus accumbens.

一个名为“伏隔核”区域多巴胺的释放。

This area is part of the brain’s reward pathway,

这个区域是大脑奖赏通路的一部分，

which is sensitive to experiences that give us pleasure

它对带给我们愉悦的体验非常敏感，

and drives us to repeatedly seek them out.

并促使我们反复寻找这些体验。

The reward pathway is essential to our well-being—

奖赏通路对我们的健康至关重要，

but addictive substances also exploit it.

但成瘾物质也会利用它。

When someone is repeatedly using a substance

当有人反复使用某种物质

and their body has adapted to its presence,

并且其身体已适应该物质的存在时，

they may develop dependence

他们可能会产生依赖性，

where the drug is necessary for them to function comfortably.

此时那种物质成了他们

舒适地日常生活的必要条件。

Meanwhile, repeated use can decrease the influence of the brain’s cortex,

同时，反复使用会降低大脑皮层的影响，

which is responsible for driving deliberate decision-making

大脑皮层负责执行深思熟虑的决策

and limiting impulsive behaviors.

以及限制冲动行为；

And it can increase the influence of the brain’s subcortex,

并且还能增加大脑下皮层的影响，

which is crucial in habit-learning and impulsivity.

下皮层对习惯养成和冲动控制至关重要。

Together, these changes can make someone feel a lack of control

这些变化加在一起让人感觉无法控制

over how they’re using a substance.

自己使用一个成瘾物质的方式，

This can mean suffering in other facets of their life

这可能意味着他们 在生活的其它方面遭受折磨，

and taking risks to continue using it.

并冒险继续使用它。

If the substance leaves their system, their body's equilibrium is disrupted,

如果该物质离开他们的机体，

其身体平衡会被打破，

so they may experience cravings that motivate thoughts and behaviors

因此他们可能会产生渴望，

激发他们寻求和使用药物的想法和行为。

of seeking and using the drug.

And if they continue without the substance,

而且，如果他们继续停用该物质，

they may experience withdrawal.

他们可能会有戒断症状。

Opioids, for example, relieve pain and induce sedation.

例如，类阿片可以 缓解疼痛并诱发镇静作用，

Withdrawal from them causes heightened pain, anxiety, and insomnia.

戒断它们会加剧疼痛、焦虑和失眠。

The faster a drug reaches the brain and stimulates the reward pathway,

药物进入大脑并刺激奖赏通路速度越快，

the more addictive it is.

它就越容易成瘾。

For example, heroin and morphine have similar effects,

例如，海洛因和吗啡具有相似的作用，

but heroin’s chemical structure enhances its ability

但海洛因的化学结构增强了

to penetrate the blood-brain barrier and bind to specific receptors.

其穿透脑血屏障 及与特定受体结合的能力，

This makes it faster acting and more addictive than morphine.

这使它比吗啡起作用更快、更易成瘾。

Meanwhile, compared to nicotine patches and gum,

同时，与尼古丁贴片和尼古丁软糖相比，

regular and electronic cigarettes are more addictive

普通香烟和电子烟更容易成瘾，

because smoking and vaping deliver nicotine to the brain fastest.

因为吸香烟和电子烟 将尼古丁输送到大脑的速度最快。

Depending on their chemical structure and mode of delivery,

根据其化学结构和输送方式，

drugs vary in how addictive they are—

药物的成瘾程度各不相同，

but people also vary in how susceptible they are to substance use disorder.

但人们对物质使用障碍的 敏感程度也不尽相同。

Scientists think this is due to a mix of life experiences

科学家们认为，这是由于生活经历

and genetically inherited traits,

和基因上的遗传特征，

though neither predetermines addiction.

尽管这两者都不能预先决定成瘾。

Trauma and mental health conditions appear to make people more susceptible.

创伤和心理健康状况似乎令人更易染瘾，

And, overall, using addictive substances before 18

而且总体而言，

18 岁之前使用成瘾性物质

is considered a strong risk factor.

被认为是强风险因素，

This is in part because the reward pathways of younger brains

部分原因是年轻大脑的奖赏通路

are especially sensitive.

尤为敏感。

Many of the genetic factors at play remain unknown,

许多起作用的遗传因素仍然未知，

but some genes do seem to track with certain substance use disorders.

但有些基因似乎确实 与某些物质使用障碍有关。

For example, specific genes increase the risk for nicotine addiction

例如，特定基因会增加尼古丁成瘾风险，

by making certain receptors more sensitive to nicotine

因为它们使得某些受体 对尼古丁更加敏感，

and withdrawal from it more difficult.

也让人对尼古丁的戒断更困难。

At the same time,

同时，

some genes actually make people more resistant to substance use disorders,

某些基因其实使人们 对物质使用障碍的抵抗力更强。

such as genes that slow the breakdown of alcohol,

例如减缓酒精分解的基因，

leading to unpleasant side effects that make people less interested in drinking.

它们产生令人不快的副作用，

使人们对饮酒的兴趣降低。

In fact, one drug that treats alcohol use disorder

实际上，一种用于治疗 酒精使用障碍的药物

operates with this very mechanism.

正是通过这种机制起作用的。

Detoxing from a substance the body has become dependent on

排出一个机体已经依赖的物质

can be extremely difficult.

可能非常困难，

And in some cases, abruptly quitting can also be physically risky,

而且在某些情况下，

突然的戒断可能带来健康上的风险，

so it isn’t always advised.

因此并不总是建议这样做。

Beyond detoxing, quitting is often a long-term process.

除了排毒外，戒断通常是一个长期过程。

It’s aided by treatment plans that prioritize

治疗计划优先考虑解决

addressing underlying conditions;

潜在的问题，

developing new associations with experiences

以前与吸毒有关的经历

previously linked with drug use;

要建立新的联系，

and creating safe, supportive environments.

并创造安全的支持性环境。

Ultimately, both addiction and recovery are the results of a brain

归根结底，成瘾和康复

都是大脑从经验中

with an incredible ability to adapt from experience.

获得惊人适应能力的结果。