"What was significant about the laughter . . . was not just the fact that it provides internal exercise for a person . . .a form of jogging for the innards, but that it creates a mood in which the other positive emotions can be put to work, too." - Norman Cousins

A good laugh is a very effective treatment for depression which can ease up your facial muscles, reduces stress hormone, lowers blood pressure, increases muscle flexion, by raising levels of infection-fighting T-cells, disease-fighting proteins which produce disease-destroying antibodies, also triggers the release of endorphins, the body's natural painkillers.
Humour and laughter has beneficial effects on body, mind and spirit giving an overall sense of well being. When someone is depressed, humour and laughter boosts up a positive and hopeful attitude. When we can laugh at any problem, we feel the power and superiority to get the control over the situation. Laughter releases those uncomfortable emotions, that are bottled up in our mind and creates biochemical changes that causes damage to our soul as well as body.

People with good sense of humour fall sick less often due to the fact, laughter is an internal jogging for a man. There is a very important relationship within body and mind; emotions are registered in the body in the form of chemical messages, a complex molecule called neuropeptides, which are found throughout the body and brain, work as a means of communication. Incorporating more laughter and humour in life ensures that these molecules carrying chemical messages work positively in the body.

How to start laughing when you know you are depressed?

We have plenty of opportunities in a day when we can laugh aloud, giggle or at least smirk. Beaming all day will never cause you any harm rather uplift your spirit and you will be more welcomed by people who are around you. So notice the small incidents around you that can give you a laugh, grab those opportunities, they are too precious to let go. Every one of us has a friend or a family member who are known for their sense of humour, spend some time with him. There are email newsletters providing “A Joke a Day”, subscribe to them, watch comedy TV shows, read comics and joke books. If you have kids at home, get into tickling match with them, or you can do it with your spouse, and let them get you back with some tickle. There are thousands websites available on the internet providing you jokes for pure and loud laughs, read those jokes, share them with friends. There are funny talk shows running on T.V. and radio which can leave you rolling over your belly. Laughter is really contagious which will give you uproar to fill your soul with influx of joy. If there is something that you may not laugh at accompanied by others, like foreign language songs, public embarrassment of politicians, your obese boss trying to be smart, or a dumb colleague doing all stupid things, laugh whenever you are alone in your cabin or in the loo. This way you will not be offending anyone but do a lot of healthy exercise for your mind.

Life has different dimensions offering you spectrum of emotions , try to look at the things from different perspectives, you will see there are thousand instances of irony around you, look for events of irony in your memory warehouse, you will find plenty of them. Life is a fountainhead of fun, and depression is not enough to close that gush of joy to your life. You need to be connected to those mirthful rivers and let them flow within you.