The poorer mental function seen among alcoholics, many of whom also regularly smoke cigarettes, may be partially due to the long-term effects of nicotine, new research suggests.

"People who are also smokers are at a much higher risk," Dr. Jennifer M. Glass, of the University of Michigan's Addiction Research Center, said.

In her study, "cigarette smoking was negatively related to IQ and thinking," she said.

This finding may seem counterintuitive , since many smokers attest to feeling more alert and focused after smoking. Indeed, research shows that improved mental functioning is one of the immediate effects of nicotine exposure. Chronic smoking, however, is known to have the opposite effect.

Studies show that up to 87 percent of alcoholics smoke cigarettes. Yet, few studies have looked into cigarette smoking as a factor that might explain the cognitive deficits reported among alcoholics.

To investigate that association, Glass and her colleagues examined brain function among 172 men from the same community, including 103 men who abused alcohol.

The team found that men with higher scores on the lifetime alcohol problems scale (LAPS) and those who reported a higher number of pack-years of smoking both had lower IQ scores.

Upon further investigation, the researchers found that smoking also appeared to be independently associated with weaker verbal and visual-spatial reasoning.

Thus, though smoking did not account for all of the decreased neurocognitive functioning observed among the alcohol abusers, it did seem to account for some of the effects, the report indicates. 

中文：

最新的研究结果显示：尼古丁对人体神经的长期影响在某种程度上是嗜酒成瘾者智力下降的主要原因，因为他们中很多人同时也是老烟民。

“既喝酒又抽烟的人面临更大的危险，”密歇根大学上瘾行为研究中心的詹尼弗-M-格拉斯博士说。

她说：在研究中发现“抽烟对智商和思维能力有消极的影响。”

这一发现似乎和我们的直觉正好相反，因为很多人都觉得在抽完烟后反应会更敏捷，注意力更集中。研究结果显示，抽烟后确实会有短暂的意识功能增强，但这只是尼古丁释放的短暂效果之一。然而，长期抽烟会产生相反的效果。

研究表明87%的“酒鬼”抽烟，但是，几乎从来没有人研究过抽烟可能是导致“酒鬼”意识缺陷的原因之一。

为了调查这之间的关系，格拉斯和她的同事们研究了来自同一社区的172名男性的大脑机能，其中有103人嗜酒成瘾。

研究小组发现在终生饮酒问题表上得分较高的和那些年吸烟量越高的人，他们的智商往往比较低。

经过进一步的调查研究，研究者们发现抽烟还会直接影响一个人的语言表达能力、形象化和空间推理能力。

因此，研究报告认为，尽管抽烟并不是导致嗜酒成瘾者神经系统识别功能降低的全部原因，但确实有一定的影响。