Alice Park has a wonderful article in Time, to be an “Optimalist.”
Obesity and smoking may be the most conspicuous causes of illness in this country, but physical factors don’t account for everything. Your psychology–namely, your personality and outlook on life–can be just as important to your well-being as exercising and eating right. And especially these days, with the world’s economy tumbling toward a depression, it’s a good time to prevent yourself from slipping into one too. An entire science has grown up around the perils of negative thinking (as well as the power of positive psychology), and the latest findings confirm that a pessimistic outlook not only kindles anxiety, which can put people at risk for chronic mental illnesses like depression, but may also cause early death and set people up for a number of physical ailments, ranging from the common cold to heart disease and immune disorders. – from Time