Among other things, neuroplasticity means that emotions such as happiness and compassion can be cultivated in much the same way that a person can learn through repetition to play golf and basketball or master a musical instrument, and that such practice changes the activity and physical aspects of specific brain areas.

I think it's worth trying to do something about obvious sources of stress in your life. But even more important is learning and practicing methods to neutralize the harmful effects of stress on the body and mind. There are many possibilities, anything from meditation and yoga to listening to relaxing music. My personal favorite is simple breathing techniques - they're very effective, take very little time, and they're free.

It is unrealistic to want to be happy all the time.

Massage therapy has been shown to relieve depression, especially in people who have chronic fatigue syndrome; other studies also suggest benefit for other populations.

As a physician, I recommend nutritious hemp seeds and oil to anyone interested in maintaining a healthy diet. Everyone will benefit when American farmers can grow this amazing crop once again.

Pay attention to your body. The point is everybody is different. You have to figure out what works for you.

To be clear, I worry as much about the impact of the Internet as anyone else. I worry about shortening attention spans, the physical cost of sedentary "surfing" and the potential for coarsening discourse as millions of web pages compete for attention by appealing to our base instincts.