VOA慢速英语--科学家探索大麻如何对抗精神病

Scientists Explore How Cannabis May Fight Psychosis

British scientists have found how a substance in the cannabis plant acts in the brain to reduce abnormal¹ activity in patients at risk of psychosis.

Their findings suggest that the substance could be used in a possible treatment for the condition.

Cannabis, also known as marijuana, is illegal to grow, sell or use in many countries. Using powerful forms of cannabis can increase a person’s chances of developing psychosis. But the substance the researchers studied, the chemical cannabidiol, appears to have the opposite effect.

Cannabidiol, or CBD, is non-intoxicating². That means it is unlike drugs or alcoholic³ products, which can affect the user’s judgement or behavior.

CBD is the same cannabis substance that has also been shown to help patients with epilepsy, a disorder⁴ of the nervous system. This led to the approval in the United States of a cannabis-based drug, a specially⁵ processed form of CBD, in June.

Earlier research at King’s College London had shown that CBD seemed to block the effects of tetrahydrocannabinol, the intoxicating substance in cannabis. But how this happened was a mystery.

Now, King’s College researchers say they have more evidence of the health benefits of CBD.

Sagnik Bhattacharyya and his team gave 33 young people capsules containing the substance. All 33 subjects were experiencing signs of psychosis, although they had not been shown to have the full-blown mental condition.

The researchers studied images from the brains of the young people. They found that taking CBD capsules reduced abnormal activity in three areas of the brain: the striatum, medial temporal cortex and midbrain.

Abnormal activity in all three areas has been linked to the development of psychotic disorders⁶, such as schizophrenia.

Most current anti-psychotic drugs target the chemical dopamine. The brain uses dopamine to send signals from one nerve cell to another. But CBD works in a different way.

One major difference is that the body has an easier time dealing⁷ with CBD than other substances. CBD is less likely to cause harmful side effects, such as weight gain and other health problems linked to existing medicines.

Bhattacharyya told the Reuters news agency, “One of the reasons CBD is exciting is because it is very well tolerated compared to the other anti-psychotics we have available.”

“There is an urgent need for a safe treatment for young people at risk of psychosis,” he added.

The Institute of Psychiatry⁸, Psychology⁹ and Neuroscience at King’s College now plans a 300-patient clinical trial of CBD as a treatment.

Researchers plan to start identifying subjects for the clinical trial in early 2019.

The latest findings show the complexity¹⁰ of the combination of chemicals found within the marijuana plant. They come at a time when many countries are beginning to make their laws against cannabis less severe.

I’m Pete Musto.

Words in This Story

abnormal – adj. unusual especially in a way that causes problems

psychosis – n. a very serious mental illness that makes you behave strangely or believe things that are not true

benefit(s) – n. a good or helpful result or effect

capsule(s) – n. a very small container that is filled with medicine and swallowed whole

full-blown – adj. having all of the qualities that are associated with a particular thing or type of person

side effect(s) – n. an often harmful and unwanted effect of a drug or chemical that occurs along with the desired effect

tolerate(d) – v. to experience something harmful or unpleasant without being harmed

clinical – adj. relating to or based on work done with real patients

1 abnormal   

adj.反常的，不正常的，不规则的

参考例句：

• This warm weather is abnormal for February.二月里这种温暖的天气不太正常。
• That is simply abnormal.那简直是反常的。

2 intoxicating   

a. 醉人的,使人兴奋的

参考例句：

• Power can be intoxicating. 权力能让人得意忘形。
• On summer evenings the flowers gave forth an almost intoxicating scent. 夏日的傍晚，鲜花散发出醉人的芳香。

3 alcoholic   

adj.（含）酒精的，由酒精引起的；n.酗酒者

参考例句：

• The alcoholic strength of brandy far exceeds that of wine.白兰地的酒精浓度远远超过葡萄酒。
• Alcoholic drinks act as a poison to a child.酒精饮料对小孩犹如毒药。

4 disorder   

n.紊乱，混乱；骚动，骚乱；疾病，失调

参考例句：

• When returning back,he discovered the room to be in disorder.回家后，他发现屋子里乱七八糟。
• It contained a vast number of letters in great disorder.里面七零八落地装着许多信件。

5 specially   

adv.特定地；特殊地；明确地

参考例句：

• They are specially packaged so that they stack easily.它们经过特别包装以便于堆放。
• The machine was designed specially for demolishing old buildings.这种机器是专为拆毁旧楼房而设计的。

6 disorders   

n.混乱( disorder的名词复数 )；凌乱；骚乱；（身心、机能）失调

参考例句：

• Reports of anorexia and other eating disorders are on the increase. 据报告，厌食症和其他饮食方面的功能紊乱发生率正在不断增长。 来自《简明英汉词典》
• The announcement led to violent civil disorders. 这项宣布引起剧烈的骚乱。 来自《简明英汉词典》

7 dealing   

n.经商方法，待人态度

参考例句：

• This store has an excellent reputation for fair dealing.该商店因买卖公道而享有极高的声誉。
• His fair dealing earned our confidence.他的诚实的行为获得我们的信任。

8 psychiatry   

n.精神病学，精神病疗法

参考例句：

• The study appeared in the Amercian science Journal of Psychiatry.这个研究发表在美国精神病学的杂志上。
• A physician is someone who specializes in psychiatry.精神病专家是专门从事精神病治疗的人。

9 psychology   

n.心理，心理学，心理状态

参考例句：

• She has a background in child psychology.她受过儿童心理学的教育。
• He studied philosophy and psychology at Cambridge.他在剑桥大学学习哲学和心理学。

10 complexity   

n.复杂(性)，复杂的事物

参考例句：

• Only now did he understand the full complexity of the problem.直到现在他才明白这一问题的全部复杂性。
• The complexity of the road map puzzled me.错综复杂的公路图把我搞糊涂了。