Many years ago, Norman Cousins was diagnosed as 
  "terminally ill." He was given six months to live. His 
  chance for recovery was one in 500.

       He could see the worry, depression and anger in his 
  life contributed to, and perhaps helped cause, his disease. 
  He wondered, "If illness can be caused by negativity, can 
  wellness be created by positivity?"

       He decided to make an experiment of himself. Laughter 
  was one of the most positive activities he knew. He rented 
  all the funny movies he could find - Keaton, Chaplin, 
  Fields, the Marx Brothers. (This was before VCRs, so he had 
  to rent the actual films.) He read funny stories. He asked 
  his friends to call him whenever they said, heard or did 
  something funny.

       His pain was so great he could not sleep. Laughing for 
  10 solid minutes, he found, relieved the pain for several 
  hours so he could sleep.

       He fully recovered from his illness and lived another 
  20 happy, healthy and productive years. (His journey is 
  detailed in his book, Anatomy of an Illness.) He credits 
  visualization, the love of his family and friends, and 
  laughter for his recovery.

       Some people think laughter is a waste of time. It is a 
  luxury, they say, a frivolity, something to indulge in only 
  every so often.

       Nothing could be further from the truth. Laughter is 
  essential to our equilibrium, to our well-being, to our 
  aliveness. If we're not well, laughter helps us get well; if 
  we are well, laughter helps us stay that way.

       Since Cousins' ground-breaking subjective work, 
  scientific studies have shown that laughter has a curative 
  effect on the body, the mind and the emotions.

       So, if you like laughter, consider it sound medical 
  advice to indulge in it as often as you can. If you don't 
  like laughter, then take your medicine - laugh anyway.
       Use whatever makes you laugh - movies, sitcoms, Monty 
  Python, records, books, New Yorker cartoons, jokes, friends.
       Give yourself permission to laugh - long and loud and 
  out loud - whenever anything strikes you as funny. The 
  people around you may think you're strange, but sooner or 
  later they'll join in even if they don't know what you're 
  laughing about.

       Some diseases may be contagious, but none is as 
  contagious as the cure. . . laughter.

  
                    By Peter McWilliams

           from Chicken Soup for the Surviving Soul

  Copyright 1996 by Jack Canfield, Mark Victor Hansen, Patty 
  Aubery & Nancy Mitchell, R.N.