请将文档翻译成汉语。 Five ways to improve your mental health in 2020 1. Practice optimism In fact, a 2019 study found people with the most positive outlook had the greatest odds of living to 85 or beyond. 2. Start volunteering A new study found that people who said they would donate money to help orphans were less sensitive to an electric shock than those who declined to give. In addition, the more helpful people thought their donation would be, the less pain they felt. 3. Be grateful If you do that for one minute each morning and evening, that sense of appreciation can broaden to others in your life and bolster optimism and better mental health. 4. Bolster your social connections "The clearest message that we get from this 75-year study is this: Good relationships keep us happier and healthier. Period," Waldinger said. 5. Find your purpose Finding a sense of purpose contributes greatly to well-being and a longer, happier life, experts tell CNN.