Scientists at the University of Texas have found that some people might be addicted to getting a suntan.
The study asked 145 beach-goers
The research, published in the Archives of Dermatology, suggested up to 53% of beach-goers could be dependent on getting a tan.
Cancer experts said it provided "an interesting insight into why people continue to binge-sunbathe".
However, an addiction scientist said it was more likely to be an "extreme behaviour", rather than an addiction.
'Aware of risks'
The scientists at the University of Texas Medical Branch at Galveston used recognised criteria for assessing whether patients have drug or alcohol dependency.
They asked 145 beach-goers about their sun-seeking habits, using questions such as "do you try to cut down on the time you spend in the sun but still find yourself sun-tanning?"
Using a questionnaire based on an internationally recognised check for assessing alcohol dependency, 26% of those interviewed were classified as "ultraviolet light (UVL) tanning dependent".
But when questions from the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders were adapted for the sunbathers, 53% were classed as dependent.
Professor Richard Wagner, who led the study, said: "It's interesting that slightly modifying tools used to identify substance-related disorders, we can actually see an objective similarity between regular tanning and those disorders."
"Dermatologists often talk about people who are 'addicted to the sun' - people who know it's not good for them to be bronzed all the time, but don't seem to be able to stop tanning."
Stay in the shade 11am-3pm
Make sure you never burn
Always cover up with a T-shirt, wide brimmed hat & sunglasses
Remember to take extra care with children
Then use factor 15+ sunscreen
Source: Cancer Research UK
Cancer Research UK's SunSmart Campaign is the UK's national skin cancer prevention campaign, and estimates that skin cancer claims around 2000 lives per year in the UK, with 65,000 new cases being reported.
Previous studies have shown many people who regularly expose themselves to UV rays in order to get a tan know they are increasing their risk of developing skin cancer.
Dr Kat Arney, cancer information officer at Cancer Research UK, said: "This is a small study but it does provide some interesting insight into why people continue to binge sunbathe, despite knowing the risks."
However Colin Drummond, professor of addiction psychiatry at St George's Hospital Medical School, London, said: "I have concerns about calling everything in the world an addiction."
"There's a tendency to translate extremes of behaviour into addictions."
Professor Drummond said addictions meant a particular chemical mechanism occurred in the brain which determined a person's behaviour.
Such a mechanism had not yet been established for sunbathing, so the habit could not be labelled an addiction.
He said people tanned because they wanted to conform socially, not because they were addicted to the feeling.