What can suntanning teach us about our brains and addiction?
I was at the dermatologist this week. “Sun damage,” she said with that somber look of authority that was designed to get me to stay out of the sun and walk in the shade. “You don’t need the sun for vitamin D. And too much sun makes for more wrinkles.” I get it, and I lather on the sunblock these days, but I cannot deny that as teenagers my friends and I bathed in baby oil and even employed tin foil reflectors to enhance those rays. The truth is that being out in the sun has all kinds of salubrious effects – it releases tension, improves mood, and makes us feel better all around.
So what’s the problem? Like so many other things that can be good in moderation, too much sunshine can be trouble. In fact, some individuals show clear signs of being addicted to suntanning to the point that doctors have recently coined the term Tanorexia.
Photo courtesy of CoolClips
An addiction is defined as the persistent, compulsive use of a substance in a way that is known by the user to be physically, psychological or socially harmful. Developing tolerance such that the individual needs more and more of the substance and showing signs of withdrawal are essential features of addiction. People typically think of addictions to substances like tobacco, alcohol and heroin, but behavioral addictions, like addiction to suntanning, show similar signs of dysfunction in the brain reward system and call on us to expand our understanding of addiction and the brain.
But is it really an addiction? It may sound like a made-up malady of those who scorn the fake-bake tan. But tanning addiction is increasingly being recognized as a serious condition with real public health implications as well as psychological and functional suffering. Excessive indoor tanners often do actually meet symptom criteria for substance abuse and dependence – spending excessive hours absorbing those UV lights and living in fear of their tan fading.
Tanning Dependence and other Psychiatric Disorders. Addiction to tanning is likely to be associated with other mental disorders. Individuals who screen positive for tanning dependence are also more likely to screen positive for Body Dysmorphic Disorder, Seasonal Affective Disorder, and elevated stress.
From Class I to Class II. The Food and Drug Administration classifies medical devices according to risk. Class I means the device is low risk and therefore is only minimally regulated. Indoor tanning beds were long considered Class I medical devices… that is, until UV radiation from tanning beds was shown to be strongly linked to skin cancer, skin burns, premature skin aging, and eye damage. They are now Class II.
How do behavioral addictions work? Same as with other drugs. Behaviors like tanning trigger a cascade of events in the brain – including the production of endogenous, brain-manufactured opioids. Researchers have shown in mice that chronic UV light exposure increases endorphin signaling at opioid receptors, and produces opioid-dependent state. And individuals with tanning addiction also show signs of withdrawal – when given naltrexone, a drug that blocks the endorphins produced in the skin while tanning, they show symptoms of withdrawal, including nausea and jitteriness.
What does this tell us about behavior and addiction? A little sun is good for most of us, just like a glass of red wine. But Tanorexia is an example of a behavioral addiction that works much like alcoholism in the brain. People really can get addicted to behaviors that don’t look like “substances” – think of gambling and work and exercise. What may start off as a healthy behavior that kick-starts endorphin production, can become an addiction that can wreak havoc with the brain’s reward system.
So why can some people enjoy a day at the beach (with sunblock) while others develop an addiction that conveys all kinds of health burden? It’s all in our heads, and the study of behavioral addictions like Tanorexia will be integral to better understanding the brain and reward systems that drive behavior.