【正确答案】In the reading part, it is explained that people are aware of depression. The causes of depression are explained in detail in the listening part. There is no particular reason causing depression; it is a disease that all human beings can get. People say depression can be treated easily with the determination of the patient, but this is not true. Depression can develop due to genetic factors, but those with no family history of depression can also develop depression. Difficulties in life can cause depression. For example, the loss of a close friend or family member, drastic social change, and adverse living conditions can lead to depression. Teenagers can get depression due to stress and this can lead to hormonal changes and deteriorating health.

【答案解析】[听力原文] When it comes to depression, there is no single reason. There are multiple factors such as genetic features, environmental conditions, health, various events in one's life and the person's way of thinking that impacts their reaction to such events. According to research, depression runs in families and some say there are depression-causing genes that are passed down. Yet, not every person with a depression-prone gene develops depression. Therefore, the genetic factor can be a reason, but they do not cause all cases of depression. Among various factors contributing to the onset of depression, let's take the example of events a person experiences in the course of life. Death of a close family member or a friend can give a person excessive grief and lead to depression. One's family or social environment can be a cause of depression. Teenagers say that negative, stressful, and unhappy family relationships hurt their self-esteem and lead to depression. Other factors leading to the onset of depression can be poverty, being homeless, and living in a violent neighborhood. Some teenagers may fail classes because they live in an environment hostile to learning. Their changing hormones can give a considerable impact on their feelings and ill health can give teenagers challenges or setbacks. Regardless of one's having depression genes or not, any of the factors mentioned above can cause depression. Furthermore, abusing certain substances such as alcohol and other drugs can create chemical changes inside one's brain. There are certain medical conditions that impact the hormone balance and one's feelings. Some diseases such as hypothyroidism may trigger a depression. When these medical causes are treated properly, the consequent depression disappears. Sometimes, people develop depression when there are no particularly sad or stressful events. Those with depression-prone genes are more likely to get depressed than those without such genes.