Every fall, like clockwork, Linda Krentz of Beaverton, Oregon, felt her brain go on strike. “I just couldn’t get going in the morning,” she says. “I’d get depressed and gain 10 pounds every winter and lose them again in the spring.” Then she read about seasonal affective disorder, a form of depression that occurs in fall and winter, and she saw the light literally. Every morning now she turns on a specially constructed light box for half an hour and sits in front of it to trick her brain into thinking it’s still enjoying those long summer days. It seems to work.

Krentz is not alone. Scientists estimate that 10 million Americans suffer from seasonal depression and 25 million more develop milder versions. But there’s never been definitive proof that treatment with very bright lights makes a difference. After all, it’s hard to do a double-blind test when the subjects can see for themselves whether or not the light is on. That’s why nobody has ever separated the real effects of light therapy from placebo (安慰剂) effects.

Until now, in three separate studies published last month, researchers report not only that light therapy works better than a placebo but that treatment is usually more effective in the early morning than in the evening. In two of the groups, the placebo problem was resolved by telling patients they were comparing light boxes to a new anti-depressant device that gives off negatively charged ions (离子). The third used the timing of light therapy as the control.

Why does light therapy work? No one really knows. “Our research suggests it has something to do with shifting the body’s internal clock,” says psychiatrist Dr. Lewey. The body is programmed to start the day with sunrise, he explains, and this gets later as the days get shorter. But why such subtle shifts make some people depressed and not others is a mystery.

That hasn’t stopped thousands of winter depressives from trying to heal themselves. Light boxes for that purpose are available without a doctor’s prescription. That bothers psychologist Michael Terman of Columbia University. He is worried that the boxes may be tried by patients who suffer from mental illness that can’t be treated with light. Terman has developed a questionnaire to help determine whether expert care is needed.

In any event, you should choose a reputable manufacturer. Whatever product you use should give off only visible light, because ultraviolet light damages the eyes. If you are photosensitive (对光敏感的), you may develop a rash. Otherwise, the main drawback is having to sit in front of the light for 30 to 60 minutes in the morning. That’s an inconvenience many winter depressives can live with.

Toxic positivity is the belief that no matter how difficult a situation is, people should maintain a positive mindset. This attitude doesn’t just stress the importance of optimism, it minimizes and denies (否定) any negative emotions. We all know that having a positive attitude is good for your mental well-being. 【小题1】 We all deal with painful emotions and experiences. Those emotions, while often unpleasant, are important and need to be felt and dealt with openly and honestly.

Toxic positivity can take a wide variety of forms. For example, when something bad happens, such as losing your job, people tell you to “just stay positive” or “look on the bright side.” 【小题2】 But they can also be a way of shutting down anything you might want to say about what you are experiencing.

If you’ve been affected by toxic positivity, there are things that you can do to avoid it. 【小题3】 Negative emotions can cause stress when unchecked, but they can also provide important information that can lead to beneficial changes in your life.

Be realistic about what you should feel. When you are facing a stressful situation, it’s normal to feel stressed, worried, or even fearful. Don’t expect too much from yourself. Focus on self-care and taking steps to improve your situation.

It’s okay to feel more than one thing. If you are facing a challenge, it’s possible to feel nervous about the future and also hopeful that you will succeed. 【小题4】

Focus on listening to others and showing support. When someone expresses a difficult emotion, don’t shut them down with toxic words. 【小题5】