Many bipolar people already live in a boom-or-bust financial cycle, independent of the current economy. Spending sprees, after all, are common during manic periods. However, mania can be triggered by stress, which is naturally higher during an economic crisis like the one Americans are facing now.

One of the most common contributors to early death among mentally ill patients, for instance, is smoking. While about 22% of the general population smokes, more than 75% of people with severe mental illness are tobacco-dependent. According to Glover, a study conducted by NASMHPD after the publication of its mortality study found that 44% of all cigarettes in the United States are consumed by people with psychiatric histories. “I used to run state hospitals, and we’d use cigarettes as reinforcement — ‘You did good; you get a cigarette,’” he says. “When people didn’t do well, we took away their tobacco privileges. We were part of the problem.” The agency is now working to make state mental hospitals smoke-free by 2011.

Bates and his Edinburgh colleagues drew their conclusions after looking at survey data of 973 pairs of adult twins. They found that, on average, a pair of identical twins shared more personality traits than a pair of non-identical twins. And when asked how happy they were, the identical twin pairs responded much more similarly than other twins, suggesting that both happiness and personality have a strong genetic component. The study, published in Psychological Science, went one step further: it suggested that personality and happiness do not merely coexist, but that in fact innate personality traits cause happiness. Twins who had similar scores in key traits — extroversion, calmness and conscientiousness, for example — had similar happiness scores; once those traits were accounted for, however, the similarity in twins’ happiness scores disappeared.

The merriment of one person, the researchers found, can ripple out and cause happiness in people up to three degrees away. So if you’re happy, you increase the chance of joy in your close friend by 25%; a friend of that friend enjoys a 10% increased chance. And that friend’s friend has a 5.6% higher chance

the findings suggest that depression contributes to heart disease indirectly — by fostering unhealthy behaviors like smoking — rather than directly. Certain biological factors linked with depression, such as inflammation and the levels of brain chemicals like serotonin, may play some role in heart health, researchers say, but the new study found that the factors that most increased heart disease risk in depressed people were the ones you might expect: lack of exercise and smoking.