From: rpattree2@gmail.com   
      
   Nautilus    
   BIOLOGY | HEALTH    
   Take Light, Not Drugs    
   How light therapy can treat disorders from depression to Alzheimer's disease.    
   BY KATHERINE HOBSON    
   ILLUSTRATION BY SHANNON FRESHWATER    
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   For Ryan Sherman*, a 34-year-old lawyer, something changed eight years ago   
   when he moved from Texas to Europe and then to Boston and New York City: The   
   shorter winter days of the more northern latitudes were like a dead weight on   
   his emotions. "I'd get    
   these depressions," he says. His sleep schedule changed, too, with his bedtime   
   slipping progressively later and early morning wakeups becoming increasingly   
   difficult.    
      
   He tried medication to improve his mood--"a Xanax type of thing"--but it   
   didn't make him feel better. Then, while searching online, he discovered the   
   Center for Light Treatment and Biological Rhythms at Columbia University   
   Medical Center, in Manhattan.    
   After undergoing a psychiatric consultation and filling out a questionnaire,   
   he was prescribed a light box.    
      
   Between October and March, he wakes up at 6:15 a.m. and, so as not to disturb   
   his partner, immediately heads to his living room, where he spends 30 minutes   
   basking in the box's glow. His mood lifted within a week when he started the   
   treatment about two    
   years ago. "It was an overwhelming sense of going from being a pessimist to   
   being an optimist," he says. It's a steady commitment, but a worthwhile one.   
   He can feel the effects when he falls off the light box wagon, as he did   
   recently during a    
   particularly busy time at work. "I felt my mood significantly go downhill," he   
   says. Within three days of returning to his regular doses of light, in   
   combination with a little bit of exercise, he says he felt "a significant   
   transformation."    
      
   Light therapy has become standard for treating seasonal depression like   
   Sherman's. The idea that light has a benevolent influence on mood during the   
   dark days of winter instinctively makes sense: As hazardous as sunbathing is,   
   it certainly feels good.    
   Now, research into the circadian underpinnings of chronic depression, bipolar   
   disorder, Alzheimer's disease, and fatigue suggests that light could help   
   these patients readjust too.     
      
      
      
   Researchers have known for decades that light influences animal behaviors;   
   exposing a rodent to light during its usual nighttime, for example, stops its   
   brain's pineal gland from producing melatonin, disturbing its sleep. And in   
   1980, a psychiatrist    
   named Alfred Lewy, then at the National Institute of Mental Health, published   
   a report in Science showing that humans were similarly vulnerable to a bright   
   light's effects.1    
      
   Months before the paper was submitted, Lewy was contacted by Herb Kern, an   
   engineer who had meticulously recorded his severe mood swings for years. Kern   
   noticed that his depressions peaked during the short winter days and then   
   retreated as the days grew    
   longer. He had combed through studies on light and melatonin and wondered if   
   it had any bearing on his sadness.    
      
   Lewy and his colleagues asked Kern to sit by a bright light in the winter   
   mornings and evenings to mimic the longer days of spring. Kern responded   
   quickly, his description of light's effects sounding much like Ryan Sherman's.   
   "I began to be bubbly again,"   
    he later reflected in a Science article. Kern's experience, followed by   
   further research, sparked the first scientific description of seasonal   
   affective disorder, or SAD.2    
      
   Some patients accustomed to pills may not be open to the time and logistics   
   involved in sitting beside a light box early each morning.    
      
   As research into light treatment for SAD continued, it became clear that it   
   wasn't necessary to stretch the day at both ends. "You could get as quick and   
   as effective a response by presenting light in the early morning only and   
   keeping [lighting] dim    
   later on," says Michael Terman, the Columbia University psychologist who   
   treated Sherman and co-author of Reset Your Inner Clock, a book about   
   treatments targeting circadian rhythms.    
      
   Exactly how light works isn't known, but many researchers suspect that bright   
   lights help SAD sufferers by regulating their sluggish circadian clocks. Those   
   clocks involve the suprachiasmatic nucleus, or SCN, which is a small area of   
   the brain's    
   hypothalamus that dictates the rhythms of a host of bodily functions,   
   including waking, sleeping, body temperature, and alertness. Absent external   
   cues, those rhythms circulate for slightly longer than 24 hours for most   
   people. (They stabilized at 24:30    
   for a man who lived in a dark cave for two months.) But normally these rhythms   
   are harmonized with the external 24-hour day/night cycle when light hits a   
   cluster of special retinal cells that are sensitive to sunlight but not always   
   involved with vision.    
      
   People with SAD may have problems syncing their internal clocks in the winter,   
   such that darker mornings allow their body's natural rhythms to drift later.   
   Exposure to an artificial bright light in the morning usually improves their   
   moods, says Lewy,    
   presumably by changing the ebb and flow of the stress hormone cortisol or   
   other bodily processes orchestrated by the SCN.    
      
   However, circadian rhythms appear to be disturbed in non-seasonal maladies   
   too, which means there is a potential for light therapy beyond SAD, says Anna   
   Wirz-Justice, professor emeritus at the Psychiatric Hospital of the University   
   of Basel. She adds    
   that light therapy has appeal for good reason. When it works, it does so   
   quickly--usually within a week or two. Also, the side effects appear to be   
   mild: Some patients have headaches or a slight nausea at the beginning of   
   treatment, and some report    
   agitation. For researchers like Wirz-Justice, the choice to use light rather   
   than drugs for depression and other mood disorders when possible is obvious.   
   "Light is an active pharmacological agent hitting the brain," she says. But   
   does it work?    
      
      
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   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)