Seasonal affective disorder is a depression experienced by people particularly during the winter. This kind of depression occurs more frequently on people who live in those parts of world where there is less or little ＿＿（41）＿＿ to sunlight. People who have this kind of depression will experience a change in their mood when the seasons change. This experience of mood change is most apparent when the winter ＿＿（42）＿＿ with less daylight. When contracting this disease, people will have such symptoms as sleeping too much, having little energy, and feeling depressed. But these symptoms can be resolved ＿＿（43）＿＿ people receive treatment. One such a treatment includes a light therapy which enables people to receive daylight or sunlight ＿＿（44）＿＿ modern technology. For instance, people can sit before a light box and get as much light as they need for curing their disease. Nowadays scientists have made great efforts to discover different ways of reducing the discomfort this depression may cause to people. Although this kind of disease may be hard to be avoided to some people, it can be ＿＿（45）＿＿ and even cured to allow patients to have a normal life.