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     More than 2 million US teenagers have suffered a serious bout (发作) of depression in the past year,

according to a federal government survey released on Tuesday.

     On average, 8.5 percent of adolescents aged 12 to 17 described having had a major depressive episode

in the previous year, the Substance Abuse and Mental Health Services Administration reported.

     But there were "striking differences" by sex, with 12.7 percent of girls and 4.6 percent of boys affected. 

     Depression is the leading cause of suicide, which in turn is the third leading cause of death for 15 to 24

year olds in the United States.

     "Combined 2004 to 2006 data show that rates of past year major depressive experience among youths

aged 12 to 17 generally increased with increasing age," the researchers wrote.

     Researchers at SAMHSA and RTI International in Research Triangle Park, North Carolina, prepared the

report using data from the National Survey on Drug Use and Health.

     More than 67,700 youths aged 12 to 17 answered questions about mood and depression. They were also

asked to rate how depression affected them using the Sheehan Disability Scale, which measures impact on

family, friends, chores at home, work and school.

     Researchers defined a major depressive episode as two weeks or longer of depressed mood or loss of

interest or pleasure, and at least four other symptoms (症状) such as problems with sleep, energy,

concentration or self-image.

     Nearly half of the teenagers who had major depression said it severely damaged their ability to function in

at least one of the areas on the disability scale.

     "Fortunately, depression responds very well to early intervention and treatment," SAMHSA Administrator

Terry Cline said in a statement.

1. The underlined word"episode" in paragraph 2 has the similar meaning as the given word ____.

A. feeling

B. expression

C. experience

D. experiment

2. The main reasons which lead to serious depressive symptoms include ____.

A. low spirits, unhappiness, lack of sleep and poor concentration

B. poor health, sex discrimination, less energy and loss of interest

C. suicide, sadness,lack of confidence and depression

D. no family or friends or jobs or interests at all

3. What can be implied, but is not stated directly?

A. There were more girl students suffering depression than boys.

B. There were over 2 million American teens suffering depression in the past two years.

C. The students surveyed were aged between 12 and 17.

D. Depression is the third leading cause of suicide.

4. What will the following paragraph probably talk about according to the passage?

A. How to have a happy feeling.

B. How to live a comfortable life.

C. How to recover from stress.

D. How to prevent and treat depression.