Being lonely may make it harder to quit smoking, a new British study suggests. 

Using genetic and survey data from hundreds of thousands of people, researchers found that loneliness makes it more likely that someone will smoke. This type of analysis is called Mendelian randomization. 

"This method has never been applied to this question before and so the results are novel, but also tentative," said co-lead author Robyn Wootton, a senior research associate at the University of Bristol in the United Kingdom.

"We found evidence to suggest that loneliness leads to increased smoking, with people more likely to start smoking, to smoke more cigarettes and to be less likely to quit," Wootton said in a university news release. 

These data mesh with an observation that during the coronavirus pandemic, more British people are smoking. 

Senior study author Jorien Treur said, "Our finding that smoking may also lead to more loneliness is tentative, but it is in line with other recent studies that identified smoking as a risk factor for poor mental health. A potential mechanism for this relationship is that nicotine from cigarette smoke interferes with neurotransmitters such as dopamine in the brain." Treur is a visiting research associate from Amsterdam UMC. 

The researchers also looked for a connection between loneliness and drinking but found none. 

Still, if loneliness causes people to smoke, it is important to alert smoking cessation services so they can add this factor as they help people to quit, the study authors said. 

The report was published June 16 in the journal Addiction.